UNIVERSITY  OF  CALIFORNIA  PUBLICATIONS 

COLLEGE   OF   AGRICULTURE 

AGRICULTURAL   EXPERIMENT  STATION 

BERKELEY,   CALIFORNIA 


VINE   PRUNING    IN    CALIFORNIA 

PART  II 

By  FREDERIC  T.   BIOLETTI 


(Vitis  vinifera) 
The  source  of  our  cultivated  grapes 


BULLETIN  No.  246 

(October,  1914) 


UNIVERSITY  OF  CALIFORNIA  PRESS 
BERKELEY 


Benjamin  Ide  Wheeler,  President  of  the  University. 

EXPERIMENT  STATION  STAFF 
Heads  of  Divisions 

Thomas  Forsyth  Hunt,  Director. 

Eugene  W.  Hilgard,  Agricultural  Chemistry  (Emeritus). 

Edward  J.  Wickson,  Horticulture. 

Herbert  J.  Webber,  Director  Citrus  Experiment  Station;   Plant  Breeding. 

Hubert  E.  Van  Norman,  Vice  Director  and  Dean  of  the  University  Farm  School: 

Dairy  Management. 
William  A.  Setchell,  Botany. 
Myer  E.  Jaffa,  Nutrition. 

Robert  H.  Loughridge.  Soil  Chemistry  and  Physic^  (Emeritus). 
Charles  W.  Woodworth,  Entomology. 
Ralph  E.  Smith,  Plant  Pathology. 
J.  Eliot  Coit,  Citriculture. 
John  W.  Gilmore,  Agronomy. 
Charles  F.  Shaw,  Soil  Technology. 

John  W.  Gregg,  Landscape  Gardening  and  Floriculture. 
Frederic  T.  Bioletti,  Viticulture  and  Enology. 
Warren  T.  Clarke,  Agricultural  Extension. 
John  S.  Burd,  Agricultural  Chemistry. 
Charles  B.  Lipman,  Soil  Chemistry  and  Bacteriology. 
Clarence  M.  Haring,  Veterinary  Science  and  Bacteriology. 
Ernest  B.  Babcock,  Genetics. 
Gordon  H.  True,  Animal  Husbandry. 
James  T.  Barrett,  Plant  Pathology. 
Fritz  W.  Woll,  Animal  Nutrition. 
A.  V.  Stubenrauch,  Pomology. 
Walter  Mulford,  Forestry. 
William  G.  Hummel,  Agricultural  Education. 
Frank  L.  Peterson,  Farm  Mechanics. 
Frank  Adams,  Irrigation. 
David  N.  Morgan,  Assistant  to  the  Director. 
Mrs.  D.  L.  Bunnell,  Librarian. 


DIVISION  OF  VITICULTURE  AND  ENOLOGY 

Frederic  T.  Bioletti  L.  Bonnet 

W.  V.  Cruess  A.  E.  Way 

F.  0.  H.  Flossfeder  W.  F.  Oglesby 


CONTENTS 

PAET  II 

D.  The  Practice  of  Pruning 

page 
Pruning  Systems:  Ideals  of  Pruning;  Calif ornian  Systems  57 

Periods  of  Development:  Before  Planting;  Planting  64-69 

First  Season:  First  Winter  Pruning;  Staking 70-71 

Second  Season:  Summer  Pruning;  Second  Winter  Pruning  72-74 

Third  Season:   Summer  Pruning;   Third  Winter  Pruning  77-81 

Pruning  after  the  Third  Winter  83 

Fan-shaped  Vines  and  Long  Pruning;  Double-headed  Vines  88-90 

Vertical  Fruit  Canes;  Bowed  Fruit  Canes  92 

Vertical  Cordons:   Single;  Double;  Multiple 94 

Horizontal  Cordons:  Unilateral;  Bilateral 98 

Renovation  of  Imperfect  and  Misshapen  Vines  i 103 

Choice  of  System:  List  of  Varieties  for  Long,  Half -long,  and  Short  Pruning..   106 


ILLUSTRATIONS 

Fig.  21 — Forms  of  head  pruning,  spurs  and  half-long. 

Fig.  22 — Forms  of  head  pruning,  long  fruit  canes. 

Fig.  23 — Trellised  vine  with  fan-shaped  head  and  long  fruit  canes. 

Fig.  24 — Single  vertical  cordon. 

Fig.  25 — Unilateral  horizontal  cordon. 

Pig.  26 — Forms  of  cutting. 

Fig.  27 — Bundle  of  one-year  rooted  vines. 

Fig.  28 — Rooted  vine  with  single  cane. 

Pig.  29 — Rooted  vine  with  two  canes. 

Fig.  30 — Rooted  vine  with  canes  at  two  levels. 

Pig.  31 — Rooted  vine  pruned  ready  for  planting. 

Fig.  32 — Rooted  vine  with  roots  at  different  levels. 

Fig.  33 — Result  of  planting  too  deep. 

Fig.  34 — Root  growth  of  a  properly  pruned  and  properly  planted  young  vine. 

Fig.  35 — Growth  of  vine  during  the  first  summer. 

Fig.  36 — Second  winter  pruning  for  head  of  medium  height. 

Fig.  37 — Second  winter  pruning  for  high  head. 

Fig.  38 — Second  winter  pruning  of  very  vigorous  vine. 

Fig.  39 — Third  spring,  ready  for  disbudding. 

Fig.  40 — Third  spring,  cane  too  short. 

Fig.  41 — Vineyard  during  the  third  summer. 

[55] 


Fig.  42 — Crop  at  the  end  of  the  third  season. 

Fig.  43 — Three-year-old  vine  ready  for  pruning. 

Fig.  44 — Three-year-old  vine  pruned. 

Fig.  45 — Three-year-old  vines  pruned:  A,  for  vase-formed;  B,  for  fan-shaped  head. 

Fig.  46 — Four-year-old  vine  pruned  for  vase-formed  head. 

Fig.  47 — Four-year-old  vine  with  high  head. 

Fig.  48 — Seven-year-old  vine  with  fully  developed  vase-formed  head. 

Fig.  49 — Nine-year-old  vine  with  fully  developed  vase-formed  head  pruned. 

Fig.  50 — Fifteen-year-old  vineyard. 

Fig.  51 — Four-year-old  fan-shaped  vine  before  pruning. 

Fig.  52 — Four-year-old  fan-shaped  vine  after  pruning. 

Fig.  53 — Trellised  vineyard  of  Sultanina  defective. 

Fig.  54 — Trellised  Sultanina  vine  in  full  bearing. 

Fig.  o5 — Double-headed  vine  on  trellis. 

Fig.  56 — Vine  with  vertical  canes. 

Fig.  57 — Vineyard  with  vertical  fruit  canes  defective. 

Fig.  58 — Vertical  cordon,  young  vine  unpruned. 

Fig.  59 — Vertical  cordon,  young  vine  pruned. 

Fig.  60 — Vineyard  of  vertical  cordons. 

Fig.  61 — Vertical  cordon,  ultimate  form  unpruned. 

Fig.  62 — Vertical  cordon,  ultimate  form  pruned. 

Fig.  63 — Vertical  cordon  with  double  trunk. 

Fig.  64 — Half-long  pruning  of  horizontal  cordons. 

Fig.  65 — Horizontal  cordon,  unilateral,  short  pruned. 

Fig.  66 — Horizontal  cordon,  unilateral,  long  pruned,  defective. 

Fig.  67 — Vineyard  of  horizontal  cordons,  unilateral,  defective. 

Fig.  68 — Vineyard  of  horizontal  cordons,  bilateral. 

Fig.  69 — Young  vine  with  imperfect  top. 

Fig.  70 — Pruning  to  renew  imperfect  top. 


[56] 


VINE    PRUNING    IN    CALIFORNIA 

By  FREDERIC  T.  BIOLETTI 


THE  PRACTICE  OF  PRUNING 

Pruning  Systems. — There  is  a  very  large  number  of  systems  of 
pruning  applied  to  the  vine.  These  systems  differ  principally  in  the 
form  given  to  the  body  of  the  vine,  and  in  the  management  of  the 
annual  growth.  Some  of  the  differences  depend  on  variations  in  the 
nature  of  the  vines,  on  the  cultural  and  growing  conditions  of  the 
district,  and  on  the  objects  of  the  grower.  Others  are  unessential  and 
are  merely  a  matter  of  taste.  The  best  system  is  that  which  is  most 
adapted  to  all  the  conditions  of  the  particular  vineyard.  Any  system 
which  does  not  take  into  account  the  nature  of  the  vine  is  defective. 

Ideals  of  Pruning. — Before  commencing  work,  the  pruner  should 
form  a  mental  picture  of  an  ideal  vine  of  the  form  desired.  Vines 
are  subject  to  so  many  accidents  of  weather,  cultivation,  and  disease 
that,  even  with  the  greatest  care  and  skill,  it  may  be  impossible  to 
obtain  a  single  ideal  vine  in  the  vineyard.  The  ideal  vine,  however, 
must  exist  in  the  pruner 's  mind  or  all  his  vines  will  be  unnecessarily 
defective.  With  this  ideal  constantly  in  mind,  he  is  able  to  take  such 
measures  as  will  as  much  as  possible  direct  the  energies  of  the  vine  in 
the  right  direction  and  counteract  all  contrary  influences  and  thus  to 
make  each  vine  approach  as  nearly  as  possible  the  perfect  model. 

This  mental  ideal  is  particularly  necessary  in  the  treatment  of 
young  vines.  Only  when  it  is  strongly  impressed  on  the  imagination, 
is  it  possible  to  use  such  means  and  measures  as  will  most  rapidly  and 
economically  bring  the  vine  to  profitable  maturity. 

In  the  following  account  of  the  principal  systems  of  pruning 
adapted  to  Californian  conditions,  a  description  is  first  given  of  an 
ideal  mature  vine  in  full  bearing.  This  is  followed  by  a  discussion 
of  methods  of  handling  a  young  vine  to  make  it  approach  as  nearly  as 
possible  this  ideal,  and  finally  by  an  account  of  the  regular  pruning 
necessary  to  make  the  vine  produce  maximum  crops  to  a  respectable 
old  age. 

Californian  Systems. — The  systems  of  pruning  in  use  in  California  may  be 
divided  into  two  classes  according  to  the  arrangement  of  the  arms  on  the  trunk 
of  the  vine.  In  the  commonest  systems,  there  is  a  definite  head  to  the  trunk, 
from  which  all  the  arms  arise  symmetrically  at   nearly  the  same  level.     The 

[57] 


58  UNIVERSITY  OF  CALIFORNIA — EXPERIMENT  STATION 

vines  of  these  systems  may  be  called  "headed  vines."  In  the  other  systems, 
the  trunk  is  elongated  four  to  eight  feet  and  the  arms  are  distributed  regularly 
along  the  whole  or  the  greater  portion  of  its  length.  The  vines  of  these  systems, 
owing  to  the  rope-like  form  of  the  trunks,  are  called  "cordons." 

The  headed  vines  are  divided  according  to  the  length  of  the  vertical  trunk 
into  high,  2-3  feet,  medium,  1-1  y2  feet,  and  low,  0-6  inches.  The  cordons  may 
be  vertical  or  horizontal,  according  to  the  direction  of  the  trunk,  which  is  from 
four  to  eight  feet  long.  The  horizontal  cordons  may  be  single  (unilateral)  or 
composed  of  two  branches  extending  in  opposite  directions  (bilateral).  Double 
and  even  multiple  vertical  cordons  occur,  but  they  are  very  inadvisable  and 
have  no  advantages. 

The  arrangement  of  the  arms  of  a  headed  vine  may  be  symmetrical  in  all 
directions  at  an  angle  of  about  45  degrees.  Such  a  vine  is  said  to  be  "vase- 
formed,  ' '  though  the  hollow  center  which  this  term  implies  is  not  essential. 
This  is  the  form  used  in  the  great  majority  of  our  vineyards  whether  of  wine, 
raisin,  or  shipping  grapes.  It  is  suitable  for  the  "square"  system  of  planting 
and  cross  cultivation.  Where  vines  are  planted  in  the  avenue  system,  particu- 
larly when  trellised  and  where  cross  cultivation  is  impossible,  the  arms  are 
given  a  "fan-shaped"  arrangement  in  a  vertical  plane.  This  arrangement  is 
essential  for  the  economical  working  of  trellised  vines. 

On  the  vertical  or  upright  cordon,  the  arms  are  arranged  at  as  regular 
intervals  as  possible  on  all  sides  of  the  trunk  from  the  top  to  within  twelve  or 
fifteen  inches  of  the  bottom.  On  the  horizontal  cordon  the  arms  are  arranged 
similarly,  but  as  nearly  as  possible  on  the  upper  side  of  the  trunk  only. 

Each  of  these  systems  may  again  be  divided  into  two  sub-systems,  according 
to  the  management  of  the  annual  growth  or  canes.  In  one,  spurs  of  one,  two, 
or  three  eyes  are  left  for  fruit  production.  This  system  is  called  short  or  spur 
pruning.  In  the  other,  long  canes  are  left  for  fruit  production.  This  is  called 
long  or  cane  pruning.  In  rare  cases  an  intermediate  form  is  adopted  in  which 
long  spurs  or  short  canes  of  five  or  six  eyes  are  left.  In  cane  pruning,  each 
fruit  cane  is  accompanied  by  one  or  two  short  renewal  spurs.  These  must  also 
accompany  half -long  pruning.  Systems  of  pruning,  where  only  long  canes  are 
left  without  renewal  spurs,  are  not  in  use  in  California.  In  all  systems, 
replacing  spurs  are  left  wherever  and  whenever  needed. 

Other  modifications  are  introduced  by  the  manner  of  disposal  of  the  fruit 
canes.  These  may  be  tied  up  vertically  to  a  stake  driven  at  the  foot  of  each 
vine  or  bowed  in  a  circle  and  tied  to  this  same  stake,  or  they  may  be  tied 
laterally  to  wires  stretching  along  the  rows  in  a  horizontal,  ascending  or 
descending  direction. 

The  different  systems  differ  therefore  in:  ^1)  the  shape,  length,  and  direction 
of  the  trunk;  (2)  the  arrangement  of  the  arms;  (3)  the  use  of  fruit  spurs  or 
fruit  canes  with  renewal  spurs;  (4)  the  disposal  of  the  fruit  canes. 

The  principal  possibilities  are  shown  in  the  following  table: 

A.  Head  Pruning:  Vase-Form 

1.  High  trunk:        -\  r(a)   Fruit  spurs  or 

2.  Medium  trunk:  I  (b)   Half -long  canes  and  renewal  spurs  or 

3.  Low  trunk:  1  (c)   Fruit  canes  and  renewal  spurs;  canes  vertical 

1  or  bowed. 


Bulletin  246 


VINE  PRUNING  IN  CALIFORNIA 


59 


B.  Head  Pruning:  Fan-Shaped;  Trellised 

1.  High  trunk:     Fruit  canes  and  renewal  spurs;  canes  descending. 

2.  Medium  trunk:     Fruit  canes  and  renewal  spurs;   canes  horizontal  or  as- 
cending. 

C.  Cordon  Pruning 

1.  Vertical:     Spur;  half -long;  cane. 

2.  Horizontal-unilateral:     Spur;   half -long;   cane. 

3.  Horizontal-bilateral:     Spur;  half-long;  cane. 


All  possible  combinations  indicated  by  this  table  represent  24  variations. 
Some  of  these  combinations,  however,  are  not  used  and  some  are  rare.  The 
most  common  are  shown  in  figures  21,  22,  23,  24,  and  25. 


Fig.  21^ — Forms  of  head  pruning:   A,  spur  pruning  with  high  trunk;   B, 
spur  priming  with  medium  trunk;  C,  half -long  with  medium  trunk. 

Figure  21  B  represents  a  headed,  vase-formed  vine,  with  a  medium  trunk 
and  short  fruit  spurs.  This  is  the  most  common  system  used  in  all  parts  of 
California  and  is  suited  for  all  small  growing  vines  which  bear  on  the  lower 
buds,  for  most  wine  grapes  and  for  Muscats.  The  unit  of  pruning  in  this  case 
is  a  fruit  spur  of  1,  2,  or  3  internodes,  according  to  the  vigor  of  the  variety 
and  of  the  individual  cane. 

Figure  21  A  differs  from  21  B  only  in  the  higher  trunk  and  longer  arms. 
It  is  commonly  used  for  Tokay  and  other  large  growing  varieties,  especially 
when  growing  in  rich  soil  and  when  planted  far  apart. 

Figure  21  C  has  the  same  form  of  body  as  A  and  B,  except  that  the  arms 
are  somewhat  less  numerous.  The  unit  of  pruning  is  a  short  fruit  cane  of  four 
to  five  internodes,  accompanied  by  a  renewal  spur  of  one  internode.  It  is 
suited  for  vigorous  table  grapes,  which  do  not  bear  well  on  short  spurs.  It  is 
used  especially  for  the  Cornichon  and  Malaga  in  rich  soil.  This  is  a  difficult 
system  to  keep  in  good  shape  owing  to  the  tendency  for  all  the  vigor  to  go  to 
the  growth  on  the  ends  of  the  friut  canes.  It  is  difficult  to  obtain  vigorous 
canes  on  the  renewal  spurs.  Occasional  short  pruning  is  usually  necessary  to 
keep  the  vines  in  proper  shape. 


60 


UNIVERSITY  OF  CALIFORNIA EXPERIMENT  STATION 


Figure  22  A  is  similar  to  21  C  in  form,  but  the  number  of  arms  is  still 
further  reduced  to  2,  3,  or  at  most  4.  The  unit  of  pruning  is  a  fruit  cane  of 
2,y2  to  3%  feet  with  its  renewal  spur.  Owing  to  the  length  of  the  fruit  canes 
they  require  support  and  are  tied  to  a  high  stake. 


Fig.  22 — Forms  of  head  pruning:  A,  vertical  fruit 
canes  and  renewal  spurs;  B,  bowed  fruit  canes  and 
renewal  spurs. 


This  method  is  used  in  a  large  number  of  vineyards  with  Sultanina,  Sultana 
and  certain  wine  grapes,  especially  Semillon  and  Cabernet.  It  is  not  to  be 
recommended  in  any  case,  as  it  has  several  very  serious  defects. 

The  difficulty  of  obtaining  new  wood  from  the  renewal  spurs  is  even  greater 
than  in  the  system  shown  in  figure  21  C.  The  length  and  vertical  position  of 
the  fruit  canes  cause  the  main  growth  and  vigor  of  the  vine  to  be  expended  on  the 
highest  shoots.     (See  Physiological  Principles  5  and  6,  p.  23,  pt.  I).     The  renewal 


Bulletin  246  VINE  PRUNING  IN  CALIFORNIA  61 

spurs  are  thus  so  shaded  that,  even  though  their  buds  start,  the  shoots  make  but  a 
weak  growth.  The  result  is  that  at  the  following  pruning  all  the  good  new 
wood  is  at  the  top  of  the  fruit  canes  of  the  previous  year,  where  it  cannot  be 
utilized.  The  primer  has  to  choose  then  between  reverting  to  spur  pruning 
and  getting  no  crop  or  using  the  weak  growth  from  the  renewal  spurs  for 
fruit  canes,  in  which  case  he  may  get  blossoms  but  little  or  no  fruit  of  any 
value. 

Other  defects  of  this  method  are  that  the  fruiting  shoots  are  excessively 
vigorous  and  therefore  often  tend  to  drop  their  blossoms  without  setting  and 
the  fruit  when  produced  is  massed  together  so  that  it  ripens  unevenly  and  is 
difficult  to  gather.     It  also  requires  a  tall  and  expensive  stake. 

Figure  22  B  represents  an  improvement  on  the  last  system.  It  differs  only 
in  the  method  of  treating  the  fruit  canes.  These  are  bent  over  in  the  form  of 
a  circle  and  tied  by  their  middle  part  to  a  stake  which  may  be  smaller  and 
lower  than  that  needed  for  the  vertical  canes. 

This  bowing  of  the  canes  has  several  useful  effects.  The  change  of  direction 
moderates  the  tendency  of  the  vigor  of  the  vine  to  expend  itself  only  on  the 
terminal  shoots.  More  shoots  therefore  are  formed  on  the  fruit  canes  and  as 
their  vigor  is  somewhat  decreased  they  tend  to  be  more  fruitful.  The  slight 
mechanical  injury  caused  by  the  bending  operates  in  the  same  direction.  (See 
Physiological  Principle  4,  p.  22,  pt.  I.) 

The  excess  of  vigor  thus  being  diverted  from  the  fruit  canes  causes  the 
renewal  spurs  to  form  vigorous  shoots,  which  soon  grow  above  the  fruit  shoots 
and  obtain  the  light  and  air  they  need  for  their  proper  development.  This 
method  is  used  successfully  for  certain  wine  grapes  such  as  Riesling,  Cabernet, 
and  Semillon.  It  is  unsuited  to  large  vigorous  varieties  or  for  vines  on  rich 
soil  planted  wide  apart.  In  these  cases  two  fruit  canes  are  usually  insufficient 
and,  if  more  are  used,  the  grapes  and  leaves  are  so  massed  together  that  they 
are  subject  to  mildew  and  do  not  ripen  evenly  or  well.  The  bowing  and  tying 
of  the  canes  requires  considerable  skill  and  care  on  the  part  of  the  workmen. 

The  body,  arms,  and  annual  pruning  of  the  system  shown  in  figure  23  are 
similar  to  those  of  figure  22,  with  the  exception  that  the  arms  are  given  a  fan- 
shaped  arrangement  in  one  plane.  It  differs  in  the  disposal  of  the  fruit  canes, 
which  are  supported  by  a  trellis  stretching  along  the  row  from  vine  to  vine. 

This  method  is  largely  used  for  the  Sultanina  (Thompson's  Seedless),  and 
is  the  best  system  for  vigorous  vines  which  require  long  pruning,  wherever  it  is 
possible  to  dispense  with  cross  cultivation.  It  is  also  suitable  for  any  long- 
pruned  varieties  when  growing  in  very  fertile  soil. 

Figure  24  is  a  photograph  of  a  four-year-old  Emperor  vine,  illustrating  the 
vertical  cordon  system.  It  consists  of  an  upright  trunk  4i/£>  feet  high  with 
short  arms  and  fruit  spurs  scattered  evenly  and  symmetrically  from  the  top  to 
within  fifteen  inches  of  the  bottom.  This  system  is  used  in  many  Emperor 
vineyards  in  the  San  Joaquin  Valley. 

Its  advantages  are  that  it  allows  the  large  development  of  the  vine  and  the 
large  number  of  spurs  which  the  vigor  of  the  Emperor  demands,  without,  on 
the  one  hand,  crowding  the  fruit  by  the  proximity  of  the  spurs  or,  on  the 
other  hand,  spreading  the  vine  so  much  that  cultivation  is  interfered  with. 
It  also  permits  cross  cultivation. 


62 


UNIVERSITY  OF  CALIFORNIA EXPERIMENT  STATION 


Bulletin  246 


VINE  PRUNING  IN  CALIFORNIA 


63 


One  of  its  defects  is  that  the  fruit 
is  subjected  to  various  degrees  of 
temperature  and  shading  in  different 
parts  of  the  vine  and  the  ripening 
and  coloring  are  often  uneven.  A 
more  vital  defect  is  that  it  cannot 
be  maintained  permanently.  The 
arms  and  spurs  at  the  top  of  the 
trunk  tend  to  absorb  the  energies 
of  the  vine  and  the  lower  arms  and 
spurs  become  weaker  each  year  until 
finally  no  growth  at  all  is  obtained 
below.  After  several  years,  most  of 
the  vines  therefore  lose  their  char- 
acter of  cordons  and  become  simply 
headed-vines  with  abnormally  long 
trunks.     (See  figs.  61,  62.) 

The  cordon  can  be  re-established 
in  this  case  by  allowing  a  vigorous 
sucker  to  develop  one  year  from 
which  to  form  a  new  trunk  the  next. 
The  following  year  the  old  trunk  is 
removed  entirely.  An  objection  to 
this  method  is  that  it  makes  very 
large  wounds  in  the  most  vital  part 
of  the  vine — the  base  of  the  trunk. 

Figure  25  is  a  photograph  of  a 
four-year-old  Colombar  vine,  illustrat- 
ing the  unilateral,  horizontal  cordon 
system.  It  consists  of  a  trunk  about 
seven  feet  long,  supported  horizontally 
by  a  wire  two  feet  from  the  ground. 
Arms  and  spurs  are  arranged  along 
the  whole  horizontal  part  of  the  trunk 


Fig.  24 — Single  vertical  cordon  with 
fruit  spurs. 


Fig.  25 — Unilateral  horizontal  cordon  with  fruit  spurs. 


64  UNIVERSITY  OF  CALIFORNIA EXPERIMENT  STATION 

Figure  25  is  a  photograph  of  a  four-year-old  Colombar  vine,  illustrating  the 
unilateral,  horizontal  cordon  system.  It  consists  of  a  trunk  about  seven  feet 
long,  supported  horizontally  by  a  wire  two  feet  from  the  ground.  Arms  and 
spurs  are  arranged  along  the  whole  horizontal  part  of  the  trunk. 

This  system  accomplishes  the  same  objects  as  the  vertical  cordon.  It  allows 
a  large  development  of  the  vine  and  numerous  fruit  spurs  without  crowding. 
It  is  superior  to  the  vertical  cordon  in  the  distribution  of  the  fruit,  which  is 
all  exposed  to  approximately  the  same  conditions  owing  to  the  uniform  distance 
from  the  ground  of  the  fruit  spurs.  All  parts  of  the  trunk  producing  an  annual 
growth  of  wood  and  fruit  are  equally  exposed  to  light  and  the  tendency  of  the 
growth  to  occur  principally  at  the  part  of  the  trunk  farthest  removed  from  the 
root  is  counteracted  by  the  horizontal  position.  There  is  not  the  same  difficulty 
therefore  in  maintaining  this  form  of  vine  permanently  that  there  is  with  the 
vertical  cordon. 

This  system  should  not  be  used  for  small  weak  vines,  whether  the  weakness 
is  a  characteristic  of  the  variety  or  due  to  the  nature  of  the  soil.  It  is  suited 
only  to  very  vigorous  varieties  such  as  Emperor,  Almeria,  and  the  Persian  grapes 
when  growing  far  apart  in  rich,  moist  soil. 

Periods  of  Development. — The  first  year  in  the  life  of  a  vine  is  devoted  to 
developing  a  vigorous  root  system;  the  next  two  or  three  years  to  building  up 
a  shapely  trunk  and  head,  and  a  like  period  to  forming  the  full  complement  of 
arms.  At  the  end  of  from  five  to  nine  years  the  framework  of  the  vine  is 
complete  and  should  undergo  no  particular  change  of  shape  except  a  gradual 
thickening  of  trunk  and  arms. 

There  are,  therefore,  several  periods  in  the  life  of  the  vine  with  varying 
objects,  and  the  methods  of  pruning  must  vary  accordingly.  These  periods  do 
not  correspond  exactly  to  periods  of  time,  so  it  may  be  misleading  to  speak 
of  pruning  a  two-year-old1  or  a  three-year-old  vine.  One  vine  under  certain 
conditions  will  reach  the  same  stage  of  development  in  two  years  that  another 
will  reach  only  in  three  or  four  years  under  other  conditions.  The  range  of 
time  of  these  periods  is  about  as  follows: 

First  period — Formation  of  a  strong  root  system  1  to  2  years 

Second  period — Formation  of  stem  or  trunk  1  year 

Third  period — Formation  of  head  2  to  3  years 

Fourth  period — Complete  development  of  the  arms  2  to  3  years 

Total  time  of  formation  of  framework 6  to  9  years 

Under  exceptionally  favorable  conditions  the  first  and  second  periods  may 
be  included  in  the  first  year  and  a  completely  formed  vine  may  be  obtained  in 
five  years. 

Before  Planting. — For  planting,  cuttings,  one-year-old  rooted  vines. 
or  bench  grafts  are  used.  In  all  cases,  they  need  some  attention  from 
the  pruner.     In  figure  26  are  shown  the  three  forms  of  cuttings  used 


i  Age  of  Vines. — There  is  a  diversity  of  usage  in  denoting  the  age  of  a  vine. 
In  some  sections,  a  one-year-old  vine  means  a  vine  that  is  in  its  first  year.  In 
others,  it  means  a  vine  that  has  completed  its  first  year  and  is  in  its  second. 
The  former  method  is  adopted  here  as  the  most  convenient. 


Bulletin  246 


VINE  PRUNING  IN  CALIFORNIA 


65 


in  California.  They  differ  only  in  length.  The  shortest,  eight  to  ten 
inches,  are  best  suited  for  planting  in  the  nursery ;  those  of  twelve  to 
fourteen  inches  for  planting  in  the  field  in  most  cases.  The  longer 
cuttings,  sixteen  to  eighteen  inches,  are  to  be  recommended  only  in 
the  driest  soils.  In  all  cases  they  are  cut  at  the  bottom  just  below  a 
bud.  This  facilitates  the  healing  over  of  the  base,  as  roots  and  healing 
tissue  form  most  abundantly  near  a  node.  The  top  may  be  cut  just 
above  a  bud,  so  as  to  leave  the  protecting  diaphragm  or  about  one 
inch  of  internode  left,  as  in  the  figure. 


■  1  ■/ 

*  4?&si 

J  rr 
ljk(f     ''/■''        / 

1 

K>Vffl| 

WiWw^ 

%Y 

ftffol! 

\ 

JtWffli 

I 

rk 

JM 

wMfKF&>™**!& 

-Bk 

WMm 

WBkt 

Fig.  26 — Forms  of  cuttings. 


Fig.  27 — One-year-old  rooted  vines. 


Figure  27  shows  a  bundle  of  good  one-year-old  rooted  vines  as  they 
are  usually  prepared  at  the  nursery.  Before  planting  they  must  be 
pruned.  The  method  of  pruning  depends  on  the  size  and  shape  of  the 
vine  and  on  the  method  of  planting  adopted. 

Figure  28  shows  a  good  rooted  vine  of  average  size  having  a  single 
cane  at  the  top  and  several  good  roots  at  the  bottom.  The  usual  way 
to  prune  this  is  to  shorten  the  cane  to  one  or  two  buds  and  the  roots 
to  two  or  four  inches,  according  to  their  size.     Shortening  the  cane 


66 


UNIVERSITY  OF  CALIFORNIA — EXPERIMENT  STATION 


makes  the  vine  less  liable  to  dry  out  before  rooting  and  forces  the 
growth  from  the  lower  buds  which  produce  more  vigorous  shoots. 
The  roots  are  shortened  so  that  there  will  be  no  danger  of  the  ends 
being  turned  upwards  when  planted.  If  they  are  to  be  planted  in 
a  large  hole  they  may  be  left  as  long  as  five  or  six  inches;  if  to  be 
planted  with  a  crowbar  or  dibble,  they  must  be  cut  back  to  half  an 
inch. 


Fig.  28 — Rooted  vine  with 
single  cane. 


Fig.  29 — Booted  vine  with 
two  canes. 


There  is  little  if  any  advantage  in  leaving  long  pieces  of  roots. 
They  are  not  feeding  roots  and  are  of  no  use  to  the  vine  until  they 
develop  feeding  rootlets.  This  they  will  do  as  well  or  better  if  short- 
ened as  if  left  of  full  length.  The  main  advantage  of  a  rooted  vine 
over  a  cutting  is  that  it  forms  rootlets  more  easily  and  rapidly.  There 
may  be  a  slight  advantage  in  leaving  three  or  four  inches  of  the 
sound  well-grown  roots,  as  the  reserve  matters  they  contain  probably 
promote  a  better  growth  of  rootlets,  but  little  or  no  difference  has 
been  noted  between  the  growth  of  vines  of  which  the  roots  have  been 
shortened  to  one-half  inch  and  those  which  have  been  left  longer. 


Bulletin  246 


VINE  PRUNING  IN  CALIFORNIA 


67 


Where  the  roots  are  left  long,  moreover,  more  care  and  time  are  needed 
in  planting. 

If  the  rooted  vine  has  several  canes,  all  but  one  should  be  removed 
entirely,  and  this  one  shortened  to  one  or  two  eyes.  The  one  left 
should  be  that  which  is  strongest,  has  the  best  buds,  and  is  the  best 
placed.  Figure  29  shows  the  removal  of  a  cane  growing  horizontally 
and  two  buds  left  on  a  vertical  cane.    Where  a  horizontal  cane  is  left, 


Fig.   30 — Rooted  vine   with 
canes  at  two  levels. 


Fig.  31 — Eooted  vine  pruned 
ready  for  planting. 


it  should  be  cut  back  to  the  base  bud.  Otherwise  the  main  growth 
may  occur  at  a  higher  bud  and  the  vine  will  have  a  crook  which  will 
result  in  a  badly  formed  trunk. 

If  canes  are  growing  from  different  joints  as  in  figure  30,  it  is 
usually  best  to  leave  the  lower  cane  if  they  are  equally  vigorous. 
This  brings  the  buds  from  which  growth  will  come  nearer  to  the  roots, 
and  leaves  less  of  the  original  cutting,  which  are  advantages.  The 
upper  joint  between  the  canes  is,  moreover,  often  more  or  less  decayed 
or  imperfect. 


68 


UNIVERSITY  OF  CALIFORNIA EXPERIMENT  STATION 


Figure  31  shows  a  vine  pruned  and  ready  for  planting.  Bench 
grafted  vines  are  pruned  in  exactly  the  same  way,  but  in  this  case  it 
is  necessary  to  take  great  care  that  all  roots  from  near  or  above  the 
union  and  all  canes  from  near  or  below  the  union  are  removed. 

Figure  32  shows  a  vine  grown  in  the  nursery  from  an  unnecessarily 
long  cutting.  It  was  grown  in  warm,  well-drained  soil,  so  that  roots 
have  formed  at  three  levels  from  different  nodes.  Even  in  this  soil, 
however,  the  conditions  were  not  favorable  for  root  growth  at  the 
bottom,  so  the  last  two  nodes  have  formed  no  roots.     If  the  cutting 


! 

,.- 

V  '"    ' 

,.vl'-     ''i 

l''r 

- 

* 

Fig.  32 — Nursery  vine  with 
roots  at  different  levels. 


Fig.  33 — Result  of  planting  too 
deep. 


had  been  of  five  nodes  instead  of  eight  it  would  have  made  a  much 
better  vine.  The  roots  would  have  been  less  numerous,  but  more 
vigorous.  Such  a  vine  can  be  pruned  in  one  of  three  ways,  according 
to  the  character  of  the  ground  in  which  it  is  to  be  planted.  In  any 
case,  the  bottom  two  joints,  without  good  roots,  are  cut  off.  If  the 
soil  where  the  vine  is  to  be  planted  is  deep  and  dry,  the  roots  at  the 
next  three  joints  may  be  left  and  shortened  to  about  one  inch,  as 
indicated  in  the  figure.  The  roots  are  so  numerous  that  none  of  them 
have  grown  large  (see  Physiological  Principles,  p.  23,  pt.  I),  and 
nothing  would  be  gained  by  leaving  them  longer.     For  ordinary  soils 


Bulletin  246  VINE  PRUNING  IN  CALIFORNIA  69 

it  would  be  better  to  remove  the  lower  three  joints  and  for  wTet  soils 
the  lower  five. 

Figure  33  shows  the  result  of  planting  an  unnecessarily  long  cut- 
ting or  rooted  vine.  It  represents  the  lower  part  of  the  under-ground 
portion  of  a  vine  two  or  three  years  old.  The  cutting  or  rooted  vine 
was  at  least  three  joints  too  long,  and  the  lowest  part  not  only  furnishes 
no  roots  of  any  value  but  is  liable  to  decay,  which  may  spread  into 
the  rest  of  the  vine. 


Fig.  34 — Roots  of  a  young  vine  that  had  been  properly  pruned  before  planting. 

Figure  34  shows  the  root  growth  during  the  first  year  in  the  field 
of  a  rooted  vine  of  which  the  roots  had  been  properly  pruned  and 
planted  at  the  right  depth. 

Planting. — Cuttings  made  as  directed  are  planted  with  the  second 
bud  at  the  level  of  the  ground,  leaving  only  one  bud  above.  Rooted 
vines  are  planted  with  the  two  buds  just  above  the  surface.  Bench 
grafts  are  planted  with  the  union  just  one  inch  above  the  surface. 
In  the  last  case  the  soil  must  be  hilled  up  so  as  to  cover  the  union. 

First  Growing  Season. — The  treatment  during  the  first  spring  and 
summer  will  depend  on  what  growth  the  vines  are  expected  to  make 
and  on  whether  the  vines  are  staked  the  first  vear. 


70  UNIVERSITY  OF  CALIFORNIA EXPERIMENT  STATION 

With  cuttings  and  with  both  rooted  vines  and  grafts  where  the 
growth  will  be  moderate,  staking  the  first  year  is  unnecessary,  though 
it  has  some  slight  advantages.  In  these  cases,  no  pruning  of  any 
kind  is  necessary  until  the  winter  following  the  planting,  except  in 
the  case  of  bench  grafts.  The  pruning  in  the  last  case  is  confined  to 
the  removal  of  the  suckers  from  the  stock  and  roots  from  the  scion. 
If  the  stocks  have  been  well  disbudded  by  the  nurseryman,  few  suckers 
will  develop.  In  moist  soil,  the  scion  roots  may  develop  vigorously 
and  must  be  removed  before  they  grow  too  large,  or  they  may  prevent 
the  proper  development  of  the  resistant  roots. 

The  removal  of  roots  should  usually  be  done  some  time  in  July. 
For  this  purpose  the  hill  of  soil  is  scraped  away  from  the  union  and 
after  the  scion  roots  and  suckers  are  removed  it  is  replaced.  In  this 
second  hilling  up,  the  union  should  be  just  barely  covered  so  that 
the  soil  around  the  union  will  be  dry  and  unfavorable  to  a  second 
growth  of  roots.  Later  in  the  season,  about  September,  the  soil  should 
be  removed  entirely  from  around  the  union  and  any  new  roots  that 
may  have  formed  removed.  The  union  is  then  left  exposed  to  harden 
and  mature,  so  that  it  will  pass  the  winter  without  injury. 

Figure  35  shows  a  grafted  vine  in  July  after  the  union  has  been 
uncovered  for  root-cutting.  It  represents  a  good  average  vine  at  this 
period.  Such  a  vine  will  usually  support  itself  without  a  stake,  but 
if  a  stake  is  used  it  should  be  tied  to  it  loosely.  If  the  main  shoot  is 
kept  upright  it  will  be  easier  to  produce  a  well  formed  vine. 

No  disbudding,  thinning  of  shoots,  or  topping  need  be  done  in  this 
case.  The  object  is  to  have  as  abundant  a  growth  of  foliage  as  possible 
in  order  to  stimulate  a  vigorous  and  abundant  root  development.  (See 
Physiological  Principle  No.  1,  p.  22,  pt.  I.) 

In  some  cases,  where  very  good  rooted  vines  of  vigorous  varieties 
are  planted  in  rich  soil  abundantly  supplied  with  water,  it  is  desirable 
to  disbud  the  vine  early  in  order  to  throw  all  its  energies  into  the 
single  main  cane.  In  such  cases  staking  before  or  just  after  planting 
are  necessary,  and  methods  similar  to  those  described  for  the  second 
season  are  used. 

First  Winter  Pruning. — At  the  end  of  the  first  growing _g£ason.  an 
average  good  vine  will  have  produced  from  three  to  five^canes,  the 
longest  of  which  will  be  from  two  to  three  feet  long. 

Soon  after  the  leaves  have  fallen  in  December  or  early  in  January 
the  vines  should  be  pruned.  The  method  is  precisely  similar  to  that 
used  for  rooted  vines  before  planting  except  that  the  main  roots  are 
not  touched.  All  the  canes  are  removed  entirely  except  one.  This 
one  should  be  well  matured,  at  least  at  the  base,  and  should  have  well 


Bulletin  246 


VINE  PRUNING  IN  CALIFORNIA 


71 


formed  eyes.  It  is  shortened  to  two  eyes.  It  is  well  also  to  cut  off 
all  shallow  roots  within  three  or  four  inches  of  the  surface.  This  is 
necessary  in  the  case  of  grafted  vines  if  any  have  escaped  the  summer 
root-cutting. 


Fig.  35 — Growth  of  vine  during  the  first  summer. 

SottH^Khe  vines  may  have  made  an  exceptionally  large  growth. 
Such  vines  may  sometimes  possess  a  cane  large  enough  from  which 
to  start  the  trunk  in  the  way  described  later  for  the  second  winter 
pruning. 

Staking. — If  the  vines  have  not  been  staked  before,  the  stakes 
should  be  driven  soon  after  pruning  and  before  the  starting  of  the 
buds. 


72  UNIVERSITY  OF  CALIFORNIA EXPERIMENT  STxVTION 

In  order  to  preserve  the  alignment  of  the  vineyard,  the  stakes 
should  be  driven  on  the  same  side  of  every  vine  at  a  uniform  distance. 
The  best  distance  is  about  two  inches.  If  driven  closer  they  may 
injure  large  roots  or  even  the  main  underground  stem  if  the  vines 
have  not  been  carefully  planted  vertically  or  slanting  towards  the  side 
on  which  the  stake  is  to  be  placed. 

The  side  on  which  the  stake  should  be  placed  depends  on  the 
direction  of  the  prevailing  winds  during  the  growing  season.  This 
side  is  the  leeward.  That  is,  the  stake  should  be  so  placed  that  the 
wind  will  press  the  vine  towards  the  stake  instead  of  away  from  it. 
This  will  much  facilitate  the  work  of  keeping  the  vine  upright  and 
attached  to  the  stake.  If  the  vine  is  on  the  other  side  the  pressure 
of  the  wind  will  stretch  the  string  tight  and  the  swaying  of  the  vine 
will  gradually  wear  the  string  until  it  breaks,  necessitating  retying. 
By  carefully  observing  this  rule,  very  few  vines  will  require  retying 
even  if  weak  material  like  binding  twine  is  used. 

Second  Summer  Pruning. — Before  the  starting  of  the  buds,  in  the 
spring  following  the  planting,  most  of  the  vines  appear  about  the 
same  as  when  they  were  planted.  There  is,  however,  a  very  notable 
difference,  in  that  they  have  well  developed  root  systems  in  the  soil 
where  they  were  formed.  The  result  is  that  they  make  a  much  more 
prompt  and  early  start  and  will  produce  a  much  larger  growth  than 
they  did  the  first  season.  For  this  reason  they  require  verjr  careful 
attention  from  the  pruner  during  the  spring  and  summer  of  the 
second  season.  Vines  neglected  at  this  time,  in  this  respect,  may  make 
as  large  a  growth,  but  a  large  part  of  it  will  be  wasted,  the  vines  will 
be  misformed  and  it  will  require  from  one  to  two  years  longer  to 
develop  a  suitable  framework  and  to  bring  them  into  bearing,  even 
though  they  are  properly  handled  during  subsequent  years.  The 
more  vigorous  the  vines,  the  more  necessary  it  is  to  handle  them 
properly  during  this  period. 

The  main  object  during  this  second  growing  season  is  to  develop 
a  single,  strong,  vigorous  and  well  ripened  cane  from  which  to  form 
the  permanent  trunk  of  the  vine. 

This  is  done  by  concentrating  all  the  energies  of  the^Hfcinlo  the 
growth  of  a  single  shoot.  As  soon  as  the  buds  start,  or  when  the  most 
precocious  has  developed  a  shoot  of  a  few  inches  in  length,  the  vines 
should  be  disbudded.  This  consists  in  rubbing  off  with  the  hand  all 
buds  and  shoots  except  the  two  largest  and  best  placed.  The  lowest, 
upright  shoots  are  usually  the  best.  Leave  only  those  which  will  make 
a  straight  vine.    It  is  better  to  leave  less  developed  buds  than  a  shoot 


Bulletin  246  VINE  PRUNING  IN  CALIFORNIA  73 

which,  when  it  grows,  will  make  an  awkward  crook  with  the  under- 
ground stem. 

After  this  disbudding,  the  two  shoots  left  will  grow  rapidly,  as 
they  receive  all  the  energies  of  the  root  system.  When  the  longest 
have  grown  from  ten  to  fifteen  inches,  they  should  be  tied  to  the 
stake.  Unless  this  is  done,  they  are  liable  to  be  broken  off  by  any 
heavy  wind,  owing  to  their  soft,  succulent  texture.  Only  the  best 
placed  and  most  vigorous  of  the  two  shoots  should  be  tied  up.  If  this 
shoot  is  growing  upright  and  near  the  stake,  this  can  be  done  without 
any  danger  of  injuring  it.  In  this  case  the  second  shoot  should  be 
removed.  If  the  shoot  has  to  be  bent  over  in  tying  it  to  the  stake  it 
may  be  injured.  In  such  a  case  the  second  shoot  should  be  allowed 
to  grow  until  it  is  known  whether  the  first  has  been  injured.  In  case 
of  injury  the  second  shoot  can  be  tied  up  the  next  time  the  vines  are 
visited  and  the  injured  shoot  removed. 

At  the  tying' up  of  the  reserved  shoots,  all  new  shoots  which  have 
developed  since  the  first  disbudding  should  be  removed.  The  shoots 
should  be  tied  up  loosely,  as  they  are  soft  and  easily  injured,  and  they 
should  be  brought  around  carefully  to  the  windward  side  of  the  stake. 

The  shoots  will  require  tying  once  more  when  they  have  grown 
another  foot  or  eighteen  inches.  There  will  then  be  two  ties,  one  at 
two  or  three  inches  from  the  top  of  the  stake  and  the  other  at  about 
the  middle.  If  the  vines  have  a  tall  stake  and  are  to  be  headed  very 
high,  another  tying  higher  up  may  be  needed  later. 

With  vines  making  only  a  moderate  growth,  no  other  pruning  will 
be  needed  until  the  winter.  Exceptionally  vigorous  vines,  however, 
may  make  a  cane  eight,  ten  or  more  feet  long.  Such  a  cane  is  heavy 
and  is  very  likely  to  break  the  ropes  by  which  it  is  attached  to  the 
stake.  In  this  case  it  may  break  off  at  the  bottom,  or  at  least  will 
form  an  awkward  crook  near  the  ground  when  it  matures.  In  either 
case  it  is  difficult  to  form  a  good  trunk  the  following  year.  Even 
when  the  ties  do  not  break,  the  cane  will  not  be  well  suited  for  the 
commencement  of  a  trunk,  as  the  joints  will  be  so  long  that  it  will 
be  impossible  to  leave  enough  well  placed  buds  at  the  winter  pruning. 

Both  these  difficulties  are  avoided  by  timely  topping.  When  such 
vigorously  growing  canes  have  grown  twelve  or  eighteen  inches  above 
the  top  of  the  stake  they  are  cut  back  about  level  with  the  stake.  This 
is  most  conveniently  done  with  a  long-bladed  knife  or  piece  of  split 
bamboo.  After  topping,  the  cane  ceases  to  grow  in  length  and  laterals 
start  at  most  of  the  joints.  It  is  less  exposed  to  the  action  of  the  wind 
and  the  laterals  supply  the  buds  needed  for  forming  the  vine  at  the 
winter  pruning. 


74 


UNIVERSITY  OF  CALIFORNIA EXPERIMENT  STATION 


The  result  of  the  second  season's  growth,  then,  has  been  to  produce 
a  single  vigorous  cane  with  or  without  laterals.  This  is  the  cane 
which  is  to  develop  into  the  final  and  permanent  trunk  of  the  vine. 
It  must  not  only  be  large  and  vigorous,  but  must  be  properly  matured. 
If  the  vine  is  allowed  to  grow  too  late  in  the  season,  an  early  frost 
may  destroy  the  unmatured  cane  and  much  of  the  results  of  the  year's 
growth  will  be  wasted.  Such  a  frost  may  indeed  kill  the  entire  vine. 
Grafted  vines  are  particularly  liable  to  injury  from  this  cause,  as  if 
they  are  killed  down  to  the  union  they  are  completely  ruined.  Un- 
grafted  vines  when  killed  to  the  ground  may  be  renewed  from  a 
sucker  next  year.  This  sucker,  however,  is  likely  to  grow  with  such 
vigor  that  it  is  even  more  liable  to  injury  from  an  autumn  frost  than 
the  original  shoot. 

This  late  growth  is  much  more  likely  to  occur  with  young  vines 
than  with  old.  The  old  vines  stop  growing  earlier  because  their  ener- 
gies are  directed  into  the  crop,  and  as  they  produce  a  larger  amount 
of  foliage  they  draw  more  upon  the  moisture  of  the  soil,  which  there- 
fore dries  out  earlier. 

Late  growth  of  the  young  vines  must  be  prevented  and  the  wood 
matured   before   frost   if  possible.     This   is   accomplished   by  means 

which  promote  the  drying  of  the 
soil  in  autumn.  Late  irrigations 
should  be  avoided.  Cultivation 
should  usually  stop  by  mid-summer. 
In  very  moist,  rich  soils,  it  is  often 
an  advantage  to  grow  corn,  sun- 
flowers or  similar  crops  between 
the  rows  of  vines  to  take  off  the 
surplus  moisture.  In  some  cases  it 
is  good  practice  to  let  the  summer 
weeds  grow  for  the  same  purpose. 
Second  Winter  Pruning. — With 
vines  which  have  been  treated  as 
described  and  to  which  no  accident 
has  happened,  the  second  winter 
pruning  is  very  simple.  It  consists 
simply  in  cutting  back  the  single 
cane  which  has  been  allowed  to 
grow  to  the  height  at  which  it  is 
desired  to  head  the  vine. 

Figure    36    represents    a    vine 
which  has  been  cut  back  to  form  a 


Fig.  36 — Second  winter 
pruning,  for  head  of  medium 
height. 


Bulletin  246 


VINE  PRUNING  IN  CALIFORNIA 


75 


low  medium  head.  It  consists  of  a  single  cane  which  with  the  older 
wood  at  the  base  reaches  nearly  to  the  top  of  the  stake,  or  fifteen 
inches.  This  if  properly  treated  will  develop  into  a  vine  with  a  trunk 
of  about  twelve  inches,  though  this  length  can  be  modified  slightly,  as 
will  be  explained  later. 


, 

; 

Fig.    37 — Second   winter    priming, 
for  high  head. 


Fig.    38 — Second    winter    pruning 
of  very  vigorous  vine. 


This  cane  consists  of  about  seven  or  eight  joints  or  internodes,  with 
an  equal  number  of  well  formed  eyes  and  an  indefinite  number  of 
dormant  buds,  principally  near  the  base  of  the  cane  or  junction  of 
the  one-  and  two-year-old  wood.  Only  the  buds  on  the  upper  half 
of  this  cane  will  be  allowed  to  grow.    These  buds — about  four — should 


76  UNIVERSITY  OF  CALIFORNIA EXPERIMENT  STATION 

give  six  to  eight  bunches  of  grapes  and  four,  six,  or  eight  shoots  from 
which  to  form  the  spurs  at  the  following  winter  pruning. 

Figure  37  represents  a  vine  which  has  been  cut  back  to  form  a 
high  head.  The  cane  is  about  twenty-four  inches  long  and  can  be  used 
to  form  a  trunk  eighteen  inches  high,  though  this  height  can  be 
modified  as  in  the  last  case.  As  with  the  shorter  cane,  only  the  buds 
on  the  upper  half  will  be  allowed  to  produce  shoots.  These — about 
six — should  give  ten  to  twelve  bunches  and  the  shoots  necessary  for 
the  formation  of  spurs. 

Figure  38  represents  a  vigorous  vine  which  had  been  topped  during 
the  summer,  and  consequently  had  formed  well  developed  laterals. 
This  vine  has  been  cut  back  to  the  same  length  as  that  shown  in 
figure  37.  One  bud  has  been  left  of  each  lateral,  giving  thus  three 
more  buds  to  produce  grapes  and  shoots. 

In  all  cases  a  full  internode  has  been  left  above  the  top  bud.  This 
is  done  by  cutting  through  the  first  bud  above  the  highest  which  it  is 
desired  to  have  grow.  This  cut  is  made  in  such  a  way  as  to  destroy 
the  bud  but  to  leave  the  diaphragm  intact  and  part  of  the  swelling 
of  the  node.  This  upper  internode  is  left  partly  to  protect  the  upper 
bud,  but  principally  to  facilitate  tying.  By  making  a  half-hitch 
around  this  internode,  the  vine  is  held  very  firmly.  If  the  swelling 
at  the  node  of  the  destroyed  bud  is  not  left,  many  vines  will  be  pulled 
out  of  the  hitch  when  they  become  heavy  with  leaves  and  supple  with 
the  flow  of  sap  in  the  spring. 

In  tying  the  vines,  no  turns  or  hitches  must  be  made  around  any 
part  except  this  upper  internode.  A  hitch  below  the  top  bud  will 
result  in  a  crook-necked  vine,  as  the  top  will  bend  over  in  the  summer 
under  the  weight  of  the  foliage.  A  hitch  lower  down  is  even  more 
harmful,  as  it  will  girdle  and  strangle  the  vine. 

A  second  tie  about  half  way  from  the  upper  to  the  ground  is  always 
necessary  to  straighten  the  cane.  Even  if  the  cane  is  straight  when 
pruned,  a  second  tie  is  needed  to  keep  it  from  curving  under  the  pres- 
sure of  leaves  and  wind  in  the  spring.  For  high  headed  vines  three 
ties  are  usually  necessary  placed,  as  shown  in  figures  37  and  38. 

For  the  top  tie,  wire  is  particularly  suitable.  It  holds  better  than 
twine  and  does  not  wear.  Even  though  it  is  not  removed,  it  does  no 
harm,  as  the  part  around  which  it  is  wound  does  not  grow.  The 
lower  ties  should  be  of  softer  material,  as  wire  has  a  tendency  to  cut 
into  the  wood.  They  should  be  placed  so  that  the  cane  is  able  to 
expand  as  it  grows.  With  thin  and  especially  with  round  stakes  this 
means  that  the  tie  must  be  loose.  AVith  large,  square  stakes  there  is 
usually  sufficient  room  for  expansion,  even  when  the  twine  is  tied  tight. 


Bulletin  246  VINE  PRUNING  IN  CALIFORNIA  77 

However  careful  the  primer,  many  of  the  vines  cannot  be  pruned  quite 
so  simply  as  those  described.  These  methods  therefore  must  often  be  modified, 
keeping  these  vines  in  mind  as  ideals  which  the  imperfect  vines  are  made  to 
approach  as  nearly  as  may  be. 

Some  of  the  vines  may  not  make  a  sufficient  growth  of  cane  to  be  tied  up 
in  the  way  indicated.  Such  vines  should  be  pruned  back  again  to  two  buds, 
as  at  the  previous  winter  pruning,  and  special  care  taken  during  the  following 
summer  to  develop  a  good  cane.  Vines  in  which  the  development  of  the  tying- 
up  cane  is  thus  delayed  a  year  will  usually  make  a  very  vigorous  growth  the 
following  summer  and  must  be  topped.  The  result  at  the  following  winter 
pruning  will  be  a  vigorous  cane  with  laterals,  which  should  be  pruned  like  the 
vine  in  figure  38.  All  vines  which  have  not  made  a  growth  of  well  developed, 
mature  cane  of  the  length  desired  should  be  cut  back  to  two  buds.  This  length 
will  usually  be  at  least  twice  that  of  the  desired  height  of  trunk  because  the 
upper  part  of  the  cane  is  usually  badly  matured  and  with  imperfect  buds.  It 
is  bad  practice  to  cut  canes  to  intermediate  lengths,  as  this  results  usually  in 
crooked  trunks  and  inevitably  to  variations  in  the  height  of  the  heads  of 
different  vines. 

If  the  suckering,  disbudding  and  thinning  of  shoots  have  been  neglected, 
there  will  be  more  than  one  cane  on  the  vine.  In  this  case  all  but  the  strongest 
and  best  placed  must  be  removed  and  this,  treated  like  the  single  cane  in 
figures  36  and  37.  Unfortunately  the  strongest  is  often  not  the  best  placed. 
In  fact,  if  tying  up  during  the  summer  has  been  neglected  it  is  often  the 
worst  placed.  The  more  vigorous  the  vine  the  more  likely  is  the  position  of 
the  canes  to  be  defective.  This  is  especially  true  of  grafts  on  old  vines,  which 
should  be  treated  like  exceptionally  vigorous  vines  during  the  second  growing 
season.  In  these  cases  of  neglected  vines,  the  best  canes  are  often  lying  flat 
on  the  ground.  It  will  require  all  the  ingenuity  and  skill  of  the  pruner  to  get 
them  into  a  more  or  less  erect  position,  and  at  the  best  they  will  result  in 
crooked,  misshapen  vines. 

By  removing  the  soil  from  around  the  base  of  the  vine  the  cane  can  often 
be  raised  more  easily  and  the  bend  will  then  be  at  least  partially  in  the  under- 
ground stem,  where  it  is  less  harmful.  In  the  worst  cases  it  may  be  impossible 
to  raise  a  cane.  It  is  then  necessary  to  cut  all  the  canes  back  to  the  old  wood 
and  to  develop  a  new  cane  the  next  year. 

Even  if  the  main  cane  has  been  tied  up,  the  removal  of  the  other  canes,  if 
they  are  numerous  and  large,  makes  many  serious  wounds  at  the  collar  of  the 
vine,  which  in  some  cases  weaken  the  vine  considerably. 

Third  Summer  Pruning. — During  the  third  season,  average  welJ 
grown  vines,  such  as  those  represented  in  figures  36  and  37,  will 
produce  their  first  considerable  crop  and  develop  the  canes  from  which 
will  be  formed  the  first  arms. 

Figure  39  represents  such  a  vine  soon  after  the  starting  of  the 
buds  in  spring.  One  vigorous  shoot  about  three  inches  long  has  grown 
from  the  old  wood  and  five  fruit  buds  have  started  above  on  the  cane. 
All  the  buds  and  shoots  below  the  middle  of  the  cane  should  be 
removed. 


78 


UNIVERSITY  OF  CALIFORNIA EXPERIMENT  STATION 


This  will  leave  the  four  or  five  fruit  buds  and  will  give  the  vine 
the  opportunity  to  produce  eight  or  ten  bunches  of  grapes.  These 
buds  will  produce  also  at  least  four  or  five  shoots.  If  the  vine  is  very 
vigorous  and  the  season  favorable  they  may  produce  eight,  ten  or 
more. 


Fig.   39- 


-Third   spring, 
disbudding. 


read}7   for 


Fig.    40 — Third    spring,    cane    too 
short. 


This  figure  will  serve  to  illustrate  how  the  height  of  the  head  can  be 
modified  later.  When  the  five  shoots  grow,  the  height  of  the  head  will 
be  determined  at  the  next  winter  pruning  by  which  of  the  correspond- 
ing canes  are  left  as  spurs.  If  the  highest  two  canes  are  cut  back 
to  spurs  and  all  others  removed,  the  vine  will  be  headed  as  high  as 


Bulletin  246 


VINE  PRUNING  IN  CALIFORNIA 


79 


possible,  as  these  two  spurs  form  the  two  first  arms  which  determine 
the  length  of  the  trunk.  If  the  lowest  two  canes  are  chosen  and  all 
of  the  vine  above  them  removed,  the  trunk  will  be  made  as  low  as 
possible.  Intermediate  heights  can  be  obtained  by  using  some  other 
two  adjacent  canes  and  removing  the  rest.  It  is  often  advisable  to 
leave  some  extra  spurs  lower  than  it  is  desired  to  head  the  vine  and  to 
remove  these  lower  spurs  the  following  winter  after  they  have  borne 
a  crop.  For  example,  the  three  or  four  upper  canes  might  be  left,  if 
the  vine  is  vigorous  enough,  and  the  lowest  one  or  two  of  these  removed 
at  the  next  pruning.  This,  however,  is  not  often  necessary  with 
properly  handled  vines  and  is  objectionable  because  it  makes  large 
wounds  in  the  trunk. 

Figure  40  shows  a  vine  of  which  the  cane  is  too  short.  This  was 
due  to  the  accidental  breaking  off  of  the  upper  part  of  the  cane.  In 
this  case  it  is  best  to  remove  all  the  buds  and  shoots  but  the  upper- 
most two.  Otherwise  the  vine  may  head  out  too  low.  Such  a  vine 
will  usually  make  several  shoots  from  each  of  the  buds  left,  and  while 
it  will  produce  fewr  grapes  the  current  year,  it  will  be  in  proper  shape 
to  produce  a  good  crop  the  following  year. 

During  this  spring  it  will  be  necessary  to  sucker  and  remove  low 
shoots  at  least  once  more.  This  can  be  done  when  the  vines  are  hoed. 
If  the  vines  grow  vigorously  the  shoots  should  be  pinched  when  they 
are  eighteen  to  twenty-four  inches  long  to  protect  them  from  the  wind. 


Fig.  41 — Vineyard  during  the  third  summer. 


80 


UNIVERSITY  OF  CALIFORNIA EXPERIMENT  STATION 


Fig.  42 — Crop  at  end  of  third  season. 


Fig.  43 — Three-year-old  vine  ready  for  pruning. 


Bulletin  246 


VINE  PRUNING  IN  CALIFORNIA 


81 


Figure  41  shows  a  well  grown  vineyard  towards  the  end  of  the 
third  summer.  The  vines  shown  produced  at  the  rate  of  five  tons  per 
acre,  which  may  be  considered  about  two-thirds  of  a  full  crop  for 
full  bearing  vines  of  the  variety,  under  the  soil  and  climatic  conditions 
of  the  vineyard.  The  crop  of  one  of  these  vines  left  on  the  vine  until 
after  the  fall  of  the  leaves  is  shown  in  figure  42. 

Third  Winter  Pruning. — At  the  end  of  the  third  season's  growth 
the  vine  should  have  a  straight,  well  developed  trunk  with  a  number 
of  vigorous  canes  near  the  top  from  which  to  form  the  arms. 

Figure  43  represents  a  well  grown  vine  at  this  period.  No  shoots 
have  been  allowed  to  grow  on  the  lower  part  of  the  trunk  and  the 
five  buds  allowed  to  grow  above,  have  produced  nine  vigorous  canes. 
The  pruner  should  leave  enough  spurs  to  supply  all  the  fruit  buds 
that  the  vine  can  utilize.  The  number,  size,  and  thickness  of  the 
canes  show  that  the  vine  is  very  vigorous  and  can  support  a  large  crop. 
It  will  depend  somewhat  on  the  variety  how  many  buds  should  be 
left.  For  a  variety  whose  bunches  average  one  pound,  and  which 
produces  two  bunches  to  the  shoot,  twelve  fruit  buds  should  give  about 
twenty-four  pounds,  or  about  seven  tons  per  acre,  if  the  vines  are 
planted  12  by  6  feet,  as  these  were.  The  number  of  spurs  will  depend 
on  their  length.  Six  spurs  of  two 
buds  each  will  give  the  required 
number,  but  as  some  of  these  canes 
are  exceptionally  vigorous  they 
should  be  left  a  little  longer,  in 
which  case  a  smaller  number  of 
spurs  will  suffice. 

When  the  number  and  length  of 
the  spurs  is  decided  on,  the  canes 
shou]d  be  chosen  which  will  leave 
these  spurs  in  the  most  suitable 
position  for  forming  arms.  This 
position  will  depend  on  whether  we 
want  a  vase-form  or  fan-shaped 
In  the  first  case,  we  choose 
wThich  will  distribute  the 
most  evenly  and  symmetri- 
on  all  sides,  avoiding  any 
which  cross  or  point  downwards. 

In   the  second  case,   we  choose 

Fig.    44— Vine    of     Fig.    43    after 
pruning  for  vase-formed  head. 


vine, 
those 
spurs 
cally 


only  those  canes  which  run  in  the 


82  UNIVERSITY  OF  CALIFORNIA EXPERIMENT  STATION 

direction  of  the  trellis,  avoiding  canes  which  stick  out  between  the 
rows.    Downward  pointing  canes  may  be  used  in  this  case. 

Figure  44  shows  the  vine  after  pruning  for  a  vase-formed  head. 
The  pruner  has  used  two  of  the  strongest  canes  to  form  two  three-bud 
spurs  and  three  of  medium  vigor  to  form  three  two-bud  spurs.  The 
head  is  of  good  shape,  though  some  of  the  spurs  are  a  little  too  low. 


A  B 

Fig.  45 — Three-year-old  vines:  A,  pruned  for  a  vase-formed,  and  B,  for  a 

fan-shaped  head. 

One,  two.  or  three  of  these  can  be  removed  at  the  following  winter 
pruning,  and  the  permanent  arms  and  head  of  the  vine  formed  from 
canes  which  develop  on  the  two  highest  spurs.  If  the  vine  were  too 
high  the  head  could  be  developed  the  next  year  from  the  three  lowest 
spurs  and  the  upper  part  removed. 

Figure  45  shows  vines  of  the  same  age  of  practically  perfect  shape. 
Less  spurs  have  been  left  because  the  vines  were  less  vigorous.     It  is 


Bulletin  246  VINE  PRUNING  IN  CALIFORNIA  83 

easier  to  properly  shape  vines  which  make  only  a  moderate  growth 
during  the  first  three  seasons.  On  the  other  hand,  very  vigorous  vines 
can  finally  be  brought  into  practically  perfect  shape  and  the  some- 
what larger  and  more  numerous  wounds  necessary  are  more  easily 
healed  by  a  vigorous  vine. 

Pruning  after  the  Third  Winter. — For  the  pruner  who  understands 
the  pruning  of  young  vines  and  has  brought  them  to  approximately 
the  form  represented  in  figures  44  and  45,  the  subsequent  winter  prun- 
ing is  very  simple.  It  involves,  however,  one  new  idea — the  distinction 
between  fruit  and  sterile  wood. 

Up  to  the  third  winter  pruning,  this  distinction  is  not  necessary; 
first,  because  practically  all  the  wood  is  fruit  wood,  and  second,  because 
the  necessity  of  forming  the  vine  controls  the  choice  of  wood.  From 
this  time  on,  however,  this  distinction  must  be  carefully  made.  At 
each  winter  pruning  a  number  of  spurs  of  fruit  wood  must  be  left  to 
produce  the  crop  to  be  expected  from  the  size  and  vigor  of  the  vine. 
Besides  these  fruit  spurs,  it  may  be  necessary  to  leave  spurs  of  sterile 
wood  to  permit  of  increasing  the  number  of  fruit  spurs  the  following 
year. 

This  will  be  made  clear  by  comparing  figures  45  A  and  46.  Figure 
45  A  shows  a  vine  at  the  third  winter  pruning  with  two  fruit  spurs 
of  two  buds  each  and  one  fruit  spur  of  one  bud — five  fruit  buds  in  all. 

If  these  five  fruit  buds  all  produce  vigorous  shoots  during  the 
following  summer,  they  will  supply  five  canes  of  fruit  wood  which 
can  be  used  to  form  five  fruit  spurs  at  the  following  winter  pruning, 
which  will  be  about  the  normal  increase  necessary.  Some  of  these 
fruit  buds,  however,  may  produce  weak  shoots  or  shoots  so  badly  placed 
that  they  would  spoil  the  shape  of  the  head  if  used  for  spurs.  Other 
shoots,  however,  will  be  produced  from  base,  secondary  and  adventi- 
tious buds  which,  while  less  fruitful,  can  be  used  to  form  spurs  for 
the  starting  of  new  arms. 

Figure  46  shows  a  vine  after  the  fourth  winter  pruning  which  had 
developed  from  a  vine  similar  to  that  shown  in  figure  45  A.  From 
the  three  fruit  spurs  left  the  previous  year  four  canes  have  been  chosen 
for  the  fruit  spurs  of  this  year.  The  old  spur  on  the  left  has  fur- 
nished two  new  spurs  and  the  two  old  spurs  at  the  right  each  one 
new  spur.  The  pruner,  judging  that  the  vine  is  sufficiently  vigorous 
to  stand  more  wood,  has  formed  two  spurs  from  water  sprouts  which, 
while  not  likely  to  produce  much  fruit  the  first  season,  will  supply 
fruit  wood  for  the  following  year.  The  result  is  a  very  well  shaped 
vine  with  six  almost  perfectly  balanced  spurs.     These  spurs  will  de- 


84  UNIVERSITY  OF  CALIFORNIA EXPERIMENT  STATION 

velop  into  permanent  arms,  some  of  them  furnishing  finally  two  or 
three. 


Fig.  46 — Four-year-old  vine  pruned  for  vase-formed 
head. 

Figure  47  shows  a  high  headed  vine  of  the  same  age.  It  has  five 
spurs,  of  which  four  are  fruit  spurs  and  one  a  spur  of  sterile  wood  left 
t  shape  the  vine.  The  two  more  or  less  horizontal  spurs  on  the  right 
will  bear  fruit  the  following  autumn  and  will  be  removed  entirely  at 
the  following  winter  pruning,  as  they  are  badly  placed.  The  arms  of 
the  vine  will  then  be  developed  from  the  three  upright  spurs,  which 
are  excellently  placed. 


Bulletin  246 


VINE  PRUNING  IN  CALIFORNIA 


85 


Each  year  thereafter  the  same  process  must  be  followed.  First, 
enough  fruit  spurs,  as  well  placed  as  possible,  must  be  left  to  produce 
the  crop.  Second,  on  most  vines, 
supplementary  spurs  of  sterile 
wood  must  be  left  to  supply 
more  arms  where  they  are 
needed,  and  finally,  when  the 
full  complement  of  arms  has  de- 
veloped, to  supply  new  arms  to 
replace  those  which  have  become 
too  long  or  are  otherwise  de- 
fective. 

Figure  48  shows  a  fully 
formed  Carignane  vine  with  six 
well  placed  and  well  shaped 
arms.  Such  a  vine  will  proba- 
bly not  need  a  larger  number  of 
arms,  but  care  must  be  taken 
that  none  of  those  it  has  become 
too  long.  This  is  the  stage  at 
which  provision  should  be  made 
for  replacing  arms  when  they 
threaten  to  become  too  long. 
The  arm  on  the  left  will  in  two 
or  three  years  extend  too  far 
from  the  head  and  will  be  in 
danger  of  being  broken  off. 
This  year,  therefore,  a  replac- 
ing spur  should  be  left  as  near  the  head  of  the  vine  as  possible. 
Such  a  spur  can  be  formed  from  the  upright  water  sprout  which  can 
be  seen  growing  out  of  the  three-year-old  wood  of  the  arm.  One  or 
two  fruit  spurs  can  be  formed  from  the  two  fruit  canes  above  this. 
After  these  fruit  spurs  have  borne  their  crop,  the  arm  can  be  cut 
back  to  the  replacing  spur,  which  by  that  time  will  have  furnished  the 
necessary  fruit  wood.  This  cutting  back  to  shorten  or  replace  the 
arm  may  be  done  at  the  following  or  some  subsequent  winter  pruning, 
according  to  the  way  in  which  the  growth  develops. 

Sometimes  it  is  difficult  to  find  wrater  sprouts  in  suitable  positions 
for  replacing  spurs.  This  may  be  due  to  weakness  of  the  vines,  which 
are  able  only  to  develop  shoots  on  the  fruit  spurs  and  have  no  surplus 
vigor  to  force  out  dormant  buds  on  the  older  w^ood.  This  difficulty 
can  be  met  by  shorter  pruning.     If  an  arm  is  too  long,  and  at  the 


Fig.    47 — Four-year-old    vine    pruned 
for  high  vase-formed  head. 


86 


UNIVERSITY  OF  CALIFORNIA EXPERIMENT  STATION 


same  time  weak,  it  should  be  pruned  to  extra  short  spurs.  This  will 
tend  to  force  water  sprouts  to  start  from  the  older  wood  near  the  base 
of  the  arm. 


.  i 

\ 

i  \ 

W    // 

V4 

it  I    \>w 

i  111  i 

/  /  /  /  ■  /    / 

Fig.  48- 


-Seven-year-old  Carignane  vine  with  fully  developed  vase- 
formed  head. 


The  absence  of  water  sprouts  at  the  winter  pruning  may  also  be 
due  to  their  having  been  removed  during  the  summer.  When  water 
sprouts  are  removed  the  need  of  replacing  wood  should  always  be  kept 
in  mind,  and  one  vigorous,  well  placed  water  sprout  left  near  the  base 
of  every  long  arm. 


Bulletin  246 


VINE  PRUNING  IN  CALIFORNIA 


87 


Figure  49  shows  an  old  Carignane  vine  where  this  periodical  short- 
ening and  replacing  of  the  arms  has  been  done  systematically.  The 
near  side  of  the  vine  is  nearly  bare  of  arms.  At  the  previous  winter 
pruning  a  replacing  spur  was  left  right  in  the  head  of  the  vine  on 


Fig.    49 — Nine-year-old    Carignane    vine   with 
well  formed  arms. 


the  near  side.  This  produced  a  cane  which  is  utilized  this  year  as  a 
fruit  spur  and  which  will  develop  into  an  arm.  Another  similar  arm 
is  being  developed  this  year  from  a  water  sprout  growing  out  of  the 
old  wood  at  the  left. 

Figure  50  shows  an  old  vineyard  in  which  the  vines  have  been  kept 
in  good  form,  though  the  heads  are  a  little  too  low. 


88  UNIVERSITY  OF  CALIFORNIA EXPERIMENT  STATION 

Fan-shaped  Vines. — With  headed  vines,  the  treatment  up  to  the 
stage  represented  by  figures  36,  37,  and  38  is  the  same  except  for  the 
variations  in  the  height  of  the  head.  At  the  third  winter  pruning, 
however,  the  formation  of  the  head  commences,  and  the  pruner  deter- 
mines whether  it  shall  be  vase-formed  or  fan-shaped.  The  production 
of  a  vase-formed  head  has  already  been  described. 

At  the  third  winter  pruning,  the  vine  should  be  pruned  to  two 
spurs,  as  shown  in  figure  45  B.  More  vigorous  vines  should  not  be 
given  more  spurs,  as  in  figures  44  and  45  A,  but  the  spurs  should  be 
made  longer,  with  four,  five,  or  even  six  eyes  in  some  cases.  This  is 
in  order  to  obtain  some  fruit,  which  might  not  be  obtained  from  long 
pruning  varieties  by  leaving  many  spurs.     With  extremely  vigorous 


Fig.  50 — Vineyard  of  15-year-old  Carignane  vines  with  low  medium 
trunks  and  vase-formed  heads. 


vines  one  fruit  cane  may  be  left  at  this  pruning.  The  wires  of  the 
trellis  should  be  put  up  this  year,  if  this  has  not  already  been  done. 

Figures  51  and  52  illustrate  the  second  step  in  the  production  of 
a  fan-shaped  head.  This  form  of  head  is  used  only  for  trellised  vines 
and  long-pruned  varieties.  The  formation  of  the  head  and  the  man- 
agement of  the  fruit  canes  are  therefore  conveniently  discussed  to- 
gether. 

By  comparing  the  pruned  vine,  figure  52,  with  the  unpruned, 
figure  51,  the  method  of  pruning  will  be  made  clear.2  The  unpruned 
vine  shows  two  arms,  the  spurs  of  the  previous  year,  from  one 
of  which  have  grown  three  vigorous  canes  and  from  the  other  two 


2  By  mistake  the  photograph  from  which  figure  52  was  made  was  reversed, 
so  that  the  right  side  of  figure  51  corresponds  to  the  left  side  of  figure  52. 


Bulletin  246 


VINE  PRUNING  IN  CALIFORNIA 


89 


somewhat  less  vigorous.  The  pruned  vine  shows  a  complete  unit,  that 
is,  a  fruit  cane  with  its  accompanying  renewal  spur  on  the  vigorous 
side  and  a  spur  for  the  production  of  fruit  wood  for  the  following 
year  on  the  other  side.  If  the  vine  had  been  more  vigorous  two  com- 
plete units  would  have  been  left  and  one  or  two  extra  spurs. 


Fig.  51 — Before  pruning. 


Fig.  52 — After  pruning. 


As  the  form  of  the  vine  is  determined  by  the  renewal  spurs,  special 
attention  should  be  paid  to  their  position.  In  this  case,  the  middle 
cane  on  one  arm  and  the  lower  cane  on  the  other  have  been  used  for 
renewal  spurs.  This  brings  them  both  to  the  same  height  above  the 
ground  and  determines  the  place  of  the  permanent  arms.  The  next 
year  each  of  these  spurs  will  furnish  a  fruit  cane  and  one  or  two 


90 


UNIVERSITY  OF  CALIFORNIA EXPERIMENT  STATION 


renewal  spurs.  The  arms  will  thus  in  two  or  three  years  be  increased 
to  four,  or,  with  very  large  vines,  to  six.  These  spurs  should  be  chosen 
as  nearly  as  possible  in  the  plane  of  the.  trellis,  that  is,  they  should 
not  project  out  sideways.  Figures  23  and  54  show  vines  of  this  kind 
of  full  size  and  in  full  bearing. 

The  fruit  canes  also  should  be  as  nearly  as  possible  in  the  direction 
of  the  trellis,  though  this  is  not  so  important,  as  they  can  be  bent  over 
to  the  wire  when  tied  up,  and  in  any  case  they  are  removed  the  next 
year. 

Figure  53  shows  a  trellised  vineyard  of  Sultanina.  The  vines  are 
somewhat  irregular  and  proper  care  has  not  been  exercised  in  the 
choice  of  fruit  canes  and  renewal  spurs.     It  is  worse  than  useless  to 


Fig.  53 — Trellised  vineyard  of  Sultanina.     Pruning  defective. 


use  water  sprouts  or  suckers  for  fruit  canes,  and  care  in  the  selection 
of  renewal  spurs  would  have  prevented  the  awkward,  ungainly  arms. 
A  vineyard  such  as  the  one  shown  will  not  only  not  bear  so  large  a 
crop  but  will  cost  twice  as  much  to  prune  as  one  in  which  the  vines 
are  kept  in  the  proper  shape. 

Figure  54  shows  the  crop  on  a  trellised  Sultanina  pruned  by  this 
system.  It  shows  the  regular  open  distribution  of  the  grapes,  all  at 
about  the  same  distance  from  the  ground.  Such  grapes  develop  and 
ripen  equally  and  perfectly. 

Double-headed  Vines. — Some  growers  attempt  to  arrange  the  arms 
of  their  vines  in  two  stages,  one  above  the  other,  forming  double- 
headed  or  two-crowned  vines.     The  method  is  applied  to  both  vase- 


Bulletin  246 


VINE  PRUNING  IN  CALIFORNIA 


91 


orq 

01 


92 


UNIVERSITY  OF  CALIFORNIA EXPERIMENT  STATION 


formed  and  trellised  vines.  It  is  open  to  the  same  criticisms  as  the 
vertical  cordon,  the  chief  of  which  is  that  it  cannot  be  maintained 
permanently.  The  lower  head  or  ring  of  arms  finally  becomes  weak 
and  fails  to  produce  wood. 

It  is  easier  to  maintain  in  trellised  vineyards  and  has  some  ad- 
vantages, the  chief  of  which  is  that  it  makes  it  easier  to  keep  the  vine 
in  the  single  plane  and  to  prevent  arms  getting  into  the  inter-rows. 
Figure  55  illustrates  a  method  of  starting  a  double  crown  in  a  trellised 
vineyard.     The  vine  represented  is  four  or  five  years  old.     Finally, 


Fig.  55 — Trellised  vine  with  double  head. 

it  will  have  two  full  units  on  each  side.  The  double  trunk  is  not 
necessary  and  is,  in  fact,  a  disadvantage,  as  one  trunk  has  a  tendency 
to  grow  at  the  expense  of  the  other. 

Vertical  and  Bowed  Canes. — Figures  56  and  22  A  show  a  long- 
pruned  vine  in  which  the  fruit  canes  have  been  tied  vertically  to  a 
tall  stake.  This  is  a  method  used  commonly  in  many  vineyards.  The 
unit  of  pruning  is  the  same  as  in  the  method  just  described,  consisting 
of  a  fruit  cane  and  a  renewal  spur.  The  framework  of  the  vine 
consists  of  a  trunk  of  medium  height,  with  a  vase-formed  head  con- 
sisting of  three  or  four  arms.  The  defects  of  this  system  have  been 
pointed  out  on  pages  60,  61. 


Bulletin  246 


VINE  PRUNING  IN  CALIFORNIA 


93 


It  is  used  with  fair  success  with  seedless  Sultanas  and  with  some 
wine  grapes  such  as  Colombar,  Semillon,  Cabernet,  and  Reisling,  in 


Fig.  56 — Vine  with  vertical  canes. 


the  hands  of  skillful  pruners.     The  results  with  Sultanina  are  very 
unsatisfactory.     Figure  57  shows  a  vineyard  of  this  variety. 


94  UNIVERSITY  OF  CALIFORNIA EXPERIMENT  STATION 

By  this  method,  on  most  of  the  vines,  the  fruit  canes  start  from 
high  up  near  the  middle  of  the  stake,  and  are  therefore  too  short  for 
the  best  results.  The  canes  which  start  from  low  down  are  in  most 
cases  suckers,  and  therefore  of  little  value  for  fruit  bearing. 

Figure  22  B  shows  a  vine  with  bowed  canes.  The  method  of  prun- 
ing is  exactly  the  same  as  in  the  method  just  described.  The  bowing 
of  the  canes,  however,  overcomes  some  of  the  defects  of  that  method. 
It  is  used  regularly  in  many  wine  grape  vineyards  of  the  cooler  regions. 
It  is  unsuited  for  very  vigorous  vines  in  rich  soil. 

Vertical  Cordons. — In  head  pruning,  the  treatment  of  young  vines 
up  to  the  second  or  third  winter  pruning  is  identical  for  all  systems. 


Fig.  57 — Vineyard  with  vertical  fruit  canes.     Pruning  defective. 


In  cordon  pruning  the  treatment  for  the  first  and  second  is  also  the 
same.  That  is,  the  vine  is  cut  back  to  two  buds  near  the  level  of  the 
ground  until  a  cane  sufficiently  long  to  serve  for  the  formation  of  the 
trunk  is  obtained. 

In  the  vertical  cordon  the  trunk  is  three  to  four  feet  long  instead 
of  one  to  two,  as  in  head  pruning.  This  makes  it  necessary  to  have  a 
longer  and  more  vigorous  cane  to  start  with.  It  may  require  a  year 
longer  to  obtain  this.  That  is  to  say,  at  the  end  of  the  second  season 's 
growth  many  vines  will  not  have  a  single  cane  sufficiently  developed 
to  give  the  necessary  three  and  one-half  feet  of  well  ripened  wood  and 
properly  developed  buds.  At  the  second  winter  pruning,  therefore, 
it  will  often  be  necessary  to  cut  the  vine  back  to  two  buds,  as  at  the 
first  winter  pruning. 


Bulletin  246 


VINE  PRUNING  IN  CALIFORNIA 


95 


Finally,  a  cane  of  the  required  length  will  be  obtained.  The  vine 
is  then  formed  as  already  described ,  for  the  second  winter  pruning 
of  headed  vines,  except  that  the  cane  is  left  longer.    This  cane  is  then 


Fig.    58 — Vertical    cordon,    young  vine  unpruned. 


tied  to  the  stake  and  at  the  end  of  the  following  year  we  have  a  vine 
like  that  shown  in  figure  58. 

When  such  a  vine  is  pruned,  spurs  are  left  at  intervals  along  the 
trunk,  as  shown  in  figure  59.    Each  of  these  spurs  is  a  fruit  spur  and 


96  UNIVERSITY  OF  CALIFORNIA — EXPERIMENT  STATION 

is  also  the  commencement  of  an  arm.     The  future  treatment  of  these 
arms  is  the  same  as  that  of  the  arms  in  head  pruning. 

Figure  60  shows  a  six-year-old  Emperor  vineyard  pruned  in  this 
way.    It  is  in  excellent  condition,  but  cannot  long  be  kept  so.    As  the 


Fig.    59 — Vertical    cordon,    young 
vine  pruned. 


vines  become  older  it  becomes  more  and  more  difficult  to  obtain  satis- 
factory growth  on  the  lower  spurs.  Finally,  the  whole  growth  of  the 
vine  is  concentrated  at  the  top  and  instead  of  a  cordon  we  simply  have 
an  inconveniently  high-headed  vine. 

Figures  61  and  62  show  an  old  Emperor  vine  before  and  after 
pruning,  which  was  started  as  a  vertical  cordon,  but  has  finally  devel- 
oped into  the  form  described.  Such  a  vine  has  none  of  the  advantages 
of  a  cordon  and  is  inferior  to  a  headed  vine  of  moderate  height. 


Bulletin  246  VINE  PRUNING  IN  CALIFORNIA 


97 


Fig.  60 — Vineyard  of  vertical  cordons. 


\ 

^1 

sj 

#/ 

-^2 

j    \  j 

/ 

7 

/ 

■  ffiBw 

/ 

'    J« 

: 

Figs.  61  and  62 — Ultimate  form  of  a  vertical  cordon,  pruned  and  unpruned,  defectiv 


98 


UNIVERSITY  OF  CALIFORNIA EXPERIMENT  STATION 


Figure  63  shows  a  double  vertical  cordon,  which  has  no  advantage 
over  the  single  and  all  its  disadvantages.  It  is,  moreover,  more  trou- 
blesome and  costly  to  prune  and  the  bunches  are  more  difficult  to 


Fig,   63 — Vertical  cordon  with  double 
trunk  defective. 


gather  without  injury.     More  than  two  stems  are  sometimes  grown, 
which  increases  these  difficulties  and  defects. 

Horizontal  Cordons. — During  the  first  two  or  three  years,  vines 
which  are  to  be  given  the  form  of  horizontal  cordons  are  treated  ex- 


Bulletin  246  vine  PRUNING  IN  CALIFORNIA  99 

actly  as  for  vertical  cordons,  that  is,  they  are  pruned  back  to  two  buds 
each  winter  and  the  growth  forced  by  disbudding  into  a  single  cane 
during  the  summer. 

As  soon  as  a  well  ripened  cane  of  the  required  length  is  obtained, 
it  is  tied  to  a  wire  stretched  horizontally  along  the  row  at  from  fifteen 
to  twenty-four  inches  from  the  ground. 

For  this  system  of  pruning,  the  rows  should  be  twelve  to  fourteen 
feet  apart  and  the  vines  six,  seven,  or  eight  feet  apart  in  the  rows. 
As  the  cordon  or  trunk  of  each  vine  should  reach  the  next  vine,  it  will 
have  to  be  six  to  eight  feet  long.  The  best  shape  is  obtained  when  the 
trunk  is  all  formed  one  year  from  a  single  cane.  It  is  necessary, 
however,  sometimes  to  take  two  years  for  the  formation  of  the  trunk. 
In  any  case,  the  cane  first  tied  down  should  reach  at  least  half  way 
to  the  next  vine.  The  following  year  a  new  cane  from  the  end  of  this 
should  be  used  to  complete  the  full  length  of  the  trunk. 

In  attaching  the  cane  to  the  wire,  it  must  be  bent  over  in  a  gentle 
curve  and  care  taken  not  to  break  or  injure  it.  The  proper  form  of 
the  bend  is  shown  in  figures  25  and  64,  and  by  the  vine  at  the  left  side 
of  figure  65.  Sharp  bends  such  as  those  shown  by  the  vines  in  figure 
66  and  on  the  right  of  figure  65  should  be  avoided. 

The  cane  should  be  placed  on  top  of  the  wire,  but  should  not  be 
twisted  around  it.  The  end  should  be  tied  firmly  and  the  rest  of  the 
cane  supported  by  strings  tied  loosely  in  order  to  avoid  girdling  when 
the  cane  grows. 

In  the  following  spring,  most  of  the  buds  on  a  good  cane  will  start. 
If  the  cane  is  short  jointed,  some  of  the  shoots  should  be  removed  and 
only  those  shoots  allowed  to  develop  which  are  conveniently  situated 
for  permanent  arms.  If  the  vines  are  to  be  short  pruned,  the  arms 
should  be  developed  every  eight  to  twelve  inches  from  a  few  inches 
beyond  the  bend  to  the  extreme  end.  For  long  pruning,  the  arms 
should  be  farther  apart,  twelve  to  twenty  inches.  Shoots  starting 
from  the  top  of  the  cane  and  growing  vertically  upwards  are  to  be 
preferred. 

As  the  shoots  develop,  the  strongest  should  be  pinched  repeatedly, 
if  necessary.  This  will  tend  to  force  the  growth  of  the  weaker  shoots 
and  to  equalize  the  vigor  of  all.  At  the  end  of  the  season,  there  should 
be  from  five  to  ten  canes  growing  on  each  cordon  of  full  length.  These 
canes  are  then  pruned  back  to  two  or  three  buds,  or  a  little  longer  for 
long-pruned  varieties. 

During  the  following  spring  and  summer,  the  vines  should  be  care- 
fully suckered  and  unnecessary  water  sprouts  removed.  Any  shoots 
coming  from  the  lower  side  of  the  cordon  should  be  removed  earlv  to 


100 


UNIVERSITY  OF  CALIFORNIA EXPERIMENT  STATION 


strengthen  the  growth  in  the  shoots  on  the  upper  side.  Neglect  of 
this  precaution  is  shown  by  the  vines  in  figures  66  and  67.  Such  vines 
are  apt  to  become  dry  or  decayed  on  the  upper  side.  At  the  end  of 
this  year,  which  should  be  the  fourth  or  fifth  from  planting  at  the 
latest,  the  cordon  will  be  fully  formed  and  the  final  style  of  pruning 
can  be  applied.  A  short-pruned  cordon  vine  is  shown  in  figure  25. 
The  arms  and  spurs  are  a  little  too  numerous  and  too  close  together. 
If  this  vine  required  the  number  of  buds  shown  it  would  have  been 


Fig.  64 — Unilateral  horizontal  cordon  with  half-long  pruning. 


better  to  have  left  the  fruit  spurs  longer  and  to  have  left  fewer  and 
shorter  wood  spurs. 

The  upper  vine  of  figure  64  shows  a  cordon  pruned  half  long. 
This  is  an  excellent  system  for  Malaga,  Emperor,  and  Cornichon  when 
growing  in  very  fertile  soil.  It  gives  the  half-long  fruit  canes,  which 
these  varieties  need  to  produce  good  crops.  The  fruit  canes  may  be 
attached  to  a  wire  twelve  or  fifteen  inches  above  the  cordon  or  bent 
down  and  tied  to  the  cordon  itself,  as  in  the  lower  vine  of  the  figure. 


Bulletin  246 


VINE  PRUNING  IN  CALIFORNIA 


101 


The  first  method  is  the  more  convenient,  but  the  second  is  necessary 
where  there  is  difficulty  in  obtaining  satisfactory  growth  from  the 
renewal  spurs.  When  the  fruit  canes  are  tied  down,  as  indicated  in 
the  lower  vine,  renewal  spurs  may  not  be  needed,  as  vigorous  shoots 
will  usually  be  obtained  from  the  lower  buds  of  the  fruit  canes. 

Figure  65  shows  a  well  formed  cordon  in  full  bearing.  The  vine 
is  Semillon  grafted  on  St.  George  and  is  pruned  short.  The  Semillon 
is  a  variety  which  usually  requires  long  pruning,  but  the  combined 
effects  of  grafting  on  resistant  stock  and  horizontal  cordon  pruning 


Fig.  65 — Unilateral  horizontal  cordon;  var.  Semillon. 


have  increased  its  fertility  so  that  a  sufficient  crop  is  obtained  from 
short  spurs.  If  such  a  vine  were  pruned  long  it  would  quickly 
exhaust  itself,  except  in  the  richest  soil. 

Figure  66  shows  an  old  Semillon  cordon  with  several  defects.  The 
bend  is  too  short  and  the  growth  of  cane  is  all  from  the  lower  side. 
The  half -long  canes  in  this  case  will  not  exhaust  the  vine  because  most 
of  them  are  water  sprout  canes  and  will  bear  little. 

Figure  67  gives  a  view  of  the  vineyard  in  which  the  vine  of  figure 
66  grew.  Little  or  no  benefit  is  obtained  from  cordons  handled  in 
this  wav. 


102 


UNIVERSITY  OF  CALIFORNIA— EXPERIMENT  STATION 


Fig.  66 — Defective  cordon. 


fk 


"**%&&! 


IP  ■  •  issm 


**% 


Fig.  67 — Vineyard  of  horizontal  cordons,  unilateral.     Defective  pruning. 


Bulletin  246  VINE  PRUNING  IN  CALIFORNIA  103 

Figure  68  shows  a  vineyard  of  Colombar,  illustrating  a  bilateral 
cordon.  With  vines  at  the  same  distance  apart,  each  cordon  is  only 
half  the  length  of  a  unilateral  cordon.  It  is  a  little  easier  to  establish 
but  more  difficult  to  keep  in  good  form.  One  branch  tends  to  become 
stronger  than  the  other  and  in  windy  situations  the  branch  growing 
towards  the  prevailing  wind  is  more  subject  to  injury. 

Renovation  of  Imperfect  or  Misshapen  Vines. — The  pruner  with  definite  ideas 
who  properly  handles  his  vines  from  the  beginning  can,  in  most  cases,  bring 
them  into  the  required  shape  with  comparative  ease.  Often,  perhaps  usually, 
he  has  to  deal  with  vines  which  have  some  more  or  less  serious  fault.     They 


Fig.  68 — Vineyard  of  horizontal  cordons,  bilateral. 


may  be  misshapen  owing  to  defective  pruning  or  otherwise  imperfect  owing 
to  mechanical  injuries,  or  as  the  result  of  frost,  fungi,  or  insect  pests. 

If  the  vines  are  young,  the  defects  can  often  be  overcome  and  the  vine 
given  a  proper  form  very  easily. 

Figure  69  shows  a  vine  at  the  end  of  the  year  after  tying  up.  Most  of 
the  growth  has  gone  into  a  cane  near  the  base  and  the  growth  from  the  top 
buds  has  been  poor.  This  condition  is  likely  to  occur  when  a  small  or  imper- 
fectly ripened  cane  has  been  used  from  which  to  attempt  to  form  a  trunk. 
There  are  three  possible  ways  of  pruning  this  vine.  First,  the  two  small  canes 
at  the  top  can  be  cut  back  to  form  spurs  and  all  other  canes  removed.  This 
will  give  a  vine  with  the  head  at  the  right  height,  but  all  the  best  wood  has 
been  cut  off.  It  will  result  in  four  large  wounds  on  the  trunk  and  the  vine 
will  require  a  great  deal  of  attention  during  the  following  growing  season,  as 
water  sprouts  will  be  numerous  and  vigorous  on  the  lower  and  healthier  portion 


104 


UNIVERSITY  OF  CALIFORNIA EXPERIMENT  STATION 


of  the  vine.  Moreover,  the  attempt  to  force  the  growth  into  the  weak  top 
will  delay  the  development  of  the  vine  and  even  result  in  a  permanently  weak  top. 

Second,  two  or  three  of  the  canes  about  the  middle  of  the  trunk  can  be 
cut  back  to  spurs  and  the  rest  removed,  including  the  whole  top  and  the  largest 
cane  at  the  bottom.  This  will  give  a  healthier  and  stronger  vine,  but  the  head 
will  be  too  low. 

Third,  a  new  trunk  can  be  started  from  the  strong  cane  near  the  bottom  and 
the  whole  growth  above  removed,  as  shown  in  figure  70.  This  preserves  the 
strongest  cane,  on  which  most  of  the  energies  of  the  vine  was  expended  during 


Fig.  69 — Young  vine  with  imperfect  top. 


the  preceding  season,  only  one  large  wound  is  made  and  all  the  defective  and 
dwarfed  parts  of  the  vine  are  removed.  The  formation  of  the  head  is  deferred 
one  year,  but  the  vine  will  have  a  stronger,  healthier  and  better  formed  trunk 
and  will  probably  bear  as  much  the  following  year  as  if  pruned  in  either  of  the 
other  ways. 

In  any  vineyard,  many  of  the  vines,  in  some,  most  of  them,  will  show  imper- 
fections or  abnormalities  of  a  similar  nature.  No  general  rule  of  treatment 
can  be  given;  each  vine  is  a  separate  problem.  The  primer  should  endeavor  to 
choose  that  method  in  each  case  which  will  finally  and  most  quickly  give  him 
a  vine  of  the  desired  form  while  utilizing  as  much  as  practicable  the  best  and 
most  vigorous  parts  of  the  vine  and  making  as  few  and  as  small  wounds  as 
possible. 


Bulletin  24G 


VINE  PRUNING  IN  CALIFORNIA 


0;1 


As  the  vines  become  older,  it  becomes  increasingly  difficult  to  overcome 
defects  of  formation.  The  disadvantage  of  a  low  head  may  be  in  part  avoided 
by  gradually  lengthening  the  arms  and  giving  them  a  more  vertical  direction. 
An  ill-formed  head  may  be  improved  by  removing  badly  placed  arms  and 
developing  new  arms  where  needed. 

The  trunks  of  many  old  vines  are  so  defective  that  little  improvement  can 
be  obtained  by  these  means.  It  is  possible  and  occasionally  profitable  to  com- 
pletely renew  the  trunks  of  such  vines.  This  can  be  done  by  developing  a 
new  trunk  from  a  strong  cane  originating  at  or  below  the  surface  of  the  ground 
and  then  cutting  away  the  old  trunk. 


Fig.  70 — Pruning  to  renew  imperfect  top  of  vine  of  Fig.  69. 


This  method  has  the  same  defect  as  the  grafting  of  old  vines.  It  leaves  a 
large  wound  where  the  old  stump  was  removed,  a  wound  which  can  never  heal 
and  which  finally  allows  the  entrance  of  wood-rot  fungi.  Such  renewed  vines, 
however,  may  last  as  long  as  if  the  old  decayed  trunk  had  been  left  or  longer. 
They  will  also  be  more  fruitful  and  easier  to  handle  properly.  The  change  can 
be  made  without  the  loss  of  a  crop,  as  occurs  in  grafting.  If  the  stumps  are 
large,  the  expense  of  sawing  them  off  is  considerable. 

Choice  of  a  System. — In  choosing  a  system,  we  must  consider  carefully  the 
characteristics  of  the  particular  variety  we  are  growing.  A  variety  which 
bears  only  on  the  upper  buds  must  be  pruned  "long,"  that  is,  must  be  given 
fruit  canes.  It  should  be  noted  that  many  varieties,  such  as  Petite  Sirah, 
which  will  bear  with  short  pruning  when  grafted  on  resistant  roots  require 
fruit  canes  when  growing  on  their  own  roots.  In  general,  grafted  vines  require 
shorter  pruning  than  ungrafted.     If  pruned  the  same,  the  grafted  vines  may 


106  UNIVERSITY  OF  CALIFORNIA EXPERIMENT  STATION 

overbear  and  quickly  exhaust  themselves.  This  seems  to  be  the  principal  reason 
for  the  frequent  failure  of  Muscat  vines  grafted  on  resistant  stock.  The 
cultural  conditions  also  affect  the  vine  in  this  respect.  Vines  made  vigorous 
by  rich  soil,  abundant  moisture,  and  thorough  cultivation  require  longer  pruning 
than  weaker  vines  of  the  same  variety. 

The  normal  size  of  the  bunch  is  also  of  importance.  This  size  will  vary 
from  one-quarter  of  a  pound  to  2  or  3  pounds.  It  is  difficult  to  obtain  a  full 
crop  from  a  variety  whose  bunches  are  very  small  without  the  use  of  fruit 
canes.  Spurs  will  not  furnish  enough  fruit  buds  without  crowding  them  incon- 
veniently. On  the  other  hand,  some  shipping  grapes  may  bear  larger  crops 
when  pruned  long,  but  the  bunches  and  berries  may  be  too  small  for  the  best 
quality. 

The  possibilities  of  development  vary  much  with  different  varieties.  A 
Mission  or  Flame  Tokay  may  be  made  to  cover  a  quarter  of  an  acre  and 
develop  a  trunk  four  or  five  feet  in  circumference.  A  Zinfandel  vine  under 
the  same  conditions  would  not  reach  a  tenth  of  this  size  in  the  same  time. 
Vines  in  a  rich  valley  soil  will  grow  much  larger  than  on  a  poor  hillside.  The 
size  and  shape  of  the  trunk  must  be  modified  accordingly  and  adapted  to  the 
available  room  or  number  of  vines  to  the  acre. 

The  shape  of  the  vine  must  be  such  as  to  protect  it  as  much  as  possible 
from  various  unfavorable  conditions.  A  variety  susceptible  to  oidium,  like 
the  Carignane,  must  be  pruned  so  that  the  fruit  and  foliage  are  not  unduly 
massed  together.  Free  exposure  to  light  and  air  are  a  great  protection  in  this 
respect.  The  same  is  true  for  varieties  like  the  Muscat,  which  have  a  tendency 
to  "coulure''  if  the  blossoms  are  too  moist  or  shaded.  In  frosty  locations,  a 
high  trunk  will  be  a  protection,  as  the  air  is  always  colder  close  to  the  ground. 

The  qualities  required  in  the  crop  also  influence  our  choice  of  a  pruning 
system.  With  wine  grapes,  even,  perfect  ripening  and  full  flavor  are  desirable. 
These  are  obtained  best  by  having  the  grapes  at  a  uniform  height  from  the 
ground  and  as  near  to  it  as  possible.  The  same  qualities  are  desirable  in  raisin 
grapes,  with  the  addition  of  large  size  of  the  berries.  With  shipping  grapes, 
the  size  and  perfection  of  the  berries  and  bunches  are  the  most  essential  char- 
acteristics. The  vine,  therefore,  should  be  so  formed  that  each  bunch  hangs 
clear,  free  from  injurious  contact  with  canes  or  soil  and  equally  exposed  to 
light  and  air. 

The  maximum  returns  in  crop  depend  on  the  early  bearing  of  young  vines, 
the  regularity  of  bearing  of  mature  vines  and  the  longevity  of  the  vineyard. 
These  are  insured  by  careful  attention  to  all  the  details  of  pruning,  but  are 
possible  only  when  the  vines  are  given  a  suitable  form. 

The  running  expenses  of  a  vineyard  depend  in  a  great  measure  on  the  style 
of  pruning  adopted.  Vines  of  suitable  form  are  cultivated,  pruned  and  the 
crop  gathered  easily  and  cheaply.  This  depends  also  both  on  the  form  of  vine 
adopted  and  on  care  in  details. 

It  is  impossible,  therefore,  to  state  for  any  particular  variety  or  any 
particular  location  the  best  style  of  pruning  to  be  adopted.  All  that  can  be 
done  is  to  give  the  general  characteristics  of  the  variety  and  to  indicate  how 
these  may  be  modified  by  grafting,  soil  or  climatic  or  other  conditions. 

The  most  important  characteristic  of  the  variety  in  making  a  choice  of  a 
pruning  system  is  whether  it  normally  or  usually  requires  long,  half-long,  or 
long  pruning.     With  this  idea,  the  principal  grapes  grown  in  California,  together 


Bulletin  246  vine  pruning  in  California  107 

with  all  those  grown  at  the  Experiment  Station  on  which  data  exist,  have  been 
divided  into  five  groups  in  the  following  list: 

1.  Varieties  which  require  long  pruning  under  all  conditions. — Clairette  blanche, 
Corinth  white  and  black,  Seedless  Sultana,  Sultanina  white  (Thompson's  Seed- 
less) and  rose. 

2.  Varieties  which  usually  require  long  pruning. — Bastardo,  Boal  de  Madeira, 
Chardonay,  Chauche  gris  and  noir,  Colombar,  Crabbe  's  Black  Burgundy,  Durif , 
Gamais,  Kleinberger,  Luglienga,  Marsanne,  Marzemino,  Merlot,  Meunier,^  Mus- 
cadelle  de  Bordelais,  Nebbiolo,  Pagadebito,  Peverella,  Pinots,  Rieslings,  Robin 
noir,  Rulander,  Sauvignon  blanc,  Semillon,  Serine,  Petite  Sirah,  Slancamenca, 
Steinschiller,  Tinta  Cao,  Tinta  Madeira,  Trousseau,  Verdelho,  Petit  Verdot, 
Walchriesling. 

3.  Varieties  which  usually  require  short  pruning. — Aleatico,  Aligote,  Aspiran, 
Bakator,  Bouschets,  Blaue  Elbe,  Beba,  Bonarda,  Barbarossa,  Catarattu,  Char- 
bono,  Chasselas,  Freisa,  Frontignan,  Furmint,  Grand  noir,  Grosseblaue,  Green 
Hungarian,  Malmsey,  Mantuo,  Monica,  Mission,  Moscatello  fino,  Mourisco  branco, 
Mourisco  preto,  Negro  amaro,  Palomino,  Pedro  Zumbon,  Perruno,  Pizzutello  di 
Roma,  Black  Prince,  West's  White  Prolific,  Quagliano,  Rodites,  Rozaki,  Tinta 
Amarella,  Vernaccia  bianca,  Vernaccia  Sarda. 

4.  Varieties  which  require  short  pruning  under  all  conditions. — Aramon,  Burger, 
Chardonay,  Chauche  gris  and  noir,  Colombar,  Crabbe  's  Black  Burgundy,  Durif, 
Black  Morocco,  Mourastel,  Muscat  of  Alexander,  Napoleon,  Piepoule  blanc  and 
noir,  Flame  Tokay,  Ugni  blanc,  Verdal,  Zinfandel. 

5.  Varieties  of  Table  Grapes  which  usually  require  half -long  or  cordon  pruning. 
— Almeria  (Ohanez),  Bellino,  Bermestia  bianca  and  violacea,  Cipro  nero,  Dattier 
de  Beirut,  Cornichon,  Emperor,  Black  Ferrara,  Malaga,  Olivette  de  Cadenet, 
Pis-de-uhevre  blanc,  Schiradzouli,  Zabalkanski. 

These  lists  must  not  be  taken  as  indicating  absolutely  for  all  cases  how 
these  varieties  are  to  be  pruned.  They  simply  indicate  their  natural  tendencies. 
Certain  methods  and  conditions  tend  to  make  vines  more  fruitful.  Where 
these  occur,  shorter  pruning  than  is  indicated  may  be  advisable.  On  the  other 
hand,  other  methods  and  conditions  tend  to  make  the  vines  vigorous  at  the 
expense  of  fruitfulness.     Where  these  occur,  longer'  pruning  may  be  advisable. 

The  more  usual  factors  which  tend  towards  fruitfidness  are: 

Grafting  on  resistant  vines,  especially  on  certain  varieties  such  as  those  of 
Riparia  and  Berlandieri; 

Old  age  of  the  vines; 

Mechanical  or  other  injuries  to  any  part  of  the  vine; 

Large  development  of  the  trunk,  as  in  the  cordon  systems. 

The  more  usual  factors  which  tend  towards  vigor  at  the  expense  of  fruit- 
fulness  are: 

Rich  soil,  especially  large  amounts  of  humus  and  nitrogen; 

Youth  of  the  vines; 

Excessive  irrigation  or  rainfall  (within  limits). 

In  deciding  what  system  of  pruning  to  adopt,  all  these  factors,  together 
with  the  nature  of  the  vine  and  the  uses  to  which  the  fruit  is  to  be  put,  must 
be  considered.  It  is  best  when  the  vineyard  is  started  to  err  on  the  side  of 
short  pruning.  While  this  may  diminish  slightly  the  first  one  or  two  crops, 
the  vines  will  gain  in  vigor  and  the  loss  will  be  made  up  in  subsequent  crops. 


108 


UNIVERSITY  OF  CALIFORNIA EXPERIMENT  STATION 


If  the  style  of  pruning  adopted  results  in  excessive  vigor  of  the  vines,  it  should 
be  gradually  changed  in  the  direction  of  longer  pruning  with  the  object  of 
utilizing  this  vigor  in  the  production  of  crop. 

This  change  should  be  gradual,  or  the  risk  is  run  of  injuring  the  vitality  of 
the  vines  by  one  or  two  excessively  heavy  crops.  Finally,  each  year  the 
condition  of  the  individual  vine  should  determine  the  kind  of  pruning  to  be 
adopted.  If  the  vine  appears  weak,  from  whatever  cause,  it  should  be  pruned 
shorter  or  given  less  spurs  or  fruit  canes  than  the  year  before.  On  the  con- 
trary, if  it  appears  unnecessarily  vigorous,  more  or  longer  spurs  or  fruit  canes 
should  be  left.  Every  vine  should  be  judged  by  itself.  It  is  not  possible  to 
give  more  than  general  directions  for  the  pruning  of  the  whole  vineyard.  It 
cannot  be  well  pruned  unless  the  men  who  do  the  actual  pruning  are  capable 
of  using  sufficient  judgment  to  properly  modify  their  methods  for  each  individual 


vine 


